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Round

Round or rounds may refer to:
  • In shape and geometry, a circular or spherical form, or the property of roundness.
  • In mathematics, numerical rounding or round numbers.
  • In science and technology, physical roundness or applications in computing and engineering.
  • In music, a musical round, a type of canon (see Music section).
  • In sports and games, a competition round or game format.
  • In social and economic contexts, repeated activities or business funding rounds.
  • Places, such as geographical features or settlements named Round.
  • Other uses, including ammunition, tools, or cultural meanings (see Other uses section).

Shape and geometry

Definition and properties

The word "round" entered English in the period around the , derived from Anglo-French round, a variant of roond or ront, which traces back to Latin rotundus, meaning "round," "circular," or "wheel-like." This etymology emphasizes the concept of and inherent in the term. In , a round is defined as a form with a smooth, curving boundary lacking sharp angles, where points on the perimeter are equidistant or approximately equidistant from a central point, resulting in uniform . The ideal two-dimensional round is the , consisting of all points in a at a fixed distance (the r) from the center. In three dimensions, the sphere serves as the perfect round , with every point on its surface equidistant from the center, while shapes like cylinders exhibit roundness through circular cross-sections maintaining approximate uniformity in . Key properties of round shapes include high , which allows invariance under rotation around the center, and efficiency in enclosing space, as demonstrated by the : for a closed of L enclosing area A, $4\pi A \leq L^2, with holding only for . In three dimensions, achieves the minimal surface area A = 4\pi r^2 for a given , optimizing material use. Additionally, the absence of corners in round shapes distributes forces evenly, reducing concentrations compared to forms. For a circle, the circumference is given by C = 2\pi r, quantifying its boundary length. The sphere extends this ideality, with its surface area formula A = 4\pi r^2 highlighting maximal enclosure efficiency. Unlike a perfect circle or sphere, an ellipse deviates from true roundness because its points are equidistant from two foci rather than a single center, resulting in varying radii along different axes, though a circle is a special ellipse where the foci coincide.

Measurement and applications

Roundness is quantified through various measurement methods that assess deviations from an ideal or , ensuring compliance with geometric tolerances in . The circle fit method determines roundness error by minimizing the sum of squared radial deviations from a best-fit circle to the measured points on the workpiece surface. The minimum zone method, in contrast, identifies the smallest annular zone containing all points, providing a more conservative evaluation of form error as defined in standards for geometric product specifications. Simpler techniques, such as using micrometer gauges in a vee-block setup with , allow for basic roundness checks by detecting variations at multiple orientations. These methods are standardized under ISO 12181, which specifies terminology, reference profiles, and evaluation procedures for roundness of integral features like circles and cylinders. In and , roundness plays a critical role in optimizing performance across disciplines. In , rounded noses on reduce by allowing smoother separation and minimizing at off-axis angles, enhancing in flight. Ergonomically, rounded handles distribute evenly across the hand, reducing localized and the risk of repetitive strain injuries during prolonged use. In , the curved forms of domes and arches leverage roundness for structural efficiency, as their enables load distribution through , requiring less material while providing stability against gravitational forces. The pursuit of roundness has evolved historically from rudimentary innovations to advanced techniques. The of the around 3500 BCE in marked an early milestone, where rounded wooden disks facilitated transportation and laid the foundation for circular . In modern manufacturing, computer numerical control (CNC) machining achieves precise rounding through interpolated circular paths and controlled feeds, enabling complex rounded features with minimal deviation. Despite these advancements, achieving perfect roundness remains challenging due to inherent manufacturing tolerances and process variations. In , roundness deviations are typically controlled to less than 0.01 to meet functional requirements, though factors like tool deflection and material properties often necessitate post-processing corrections.

Mathematics

Numerical rounding

Numerical is the process of approximating a numerical to a specified level of , typically by replacing it with a simpler that is close in magnitude while minimizing the loss of accuracy. This technique simplifies computations, facilitates communication of results, and aligns with the inherent uncertainties in measurements. For instance, the 3.14159 might be rounded to two places as 3.14, effectively discarding the trailing digits beyond the desired . Common methods for numerical rounding include rounding to the nearest value with specific rules for handling halfway cases, as well as directional functions like floor and ceiling. The round half up method, widely used in general arithmetic, approximates a number to the nearest integer or decimal place, where values ending in 0.5 or higher round away from zero (e.g., 3.5 rounds to 4). In contrast, round half to even (also known as banker's rounding) resolves halfway cases by rounding to the nearest even digit to reduce cumulative bias over multiple operations (e.g., 3.5 rounds to 4, but 4.5 rounds to 4). The floor function returns the greatest integer less than or equal to the number (\lfloor x \rfloor), directing towards negative infinity, while the ceiling function (\lceil x \rceil) directs towards positive infinity. These methods are standardized in contexts like the IEEE 754 floating-point arithmetic, which specifies modes such as round to nearest (ties to even), round toward zero, round toward positive infinity, and round toward negative infinity to ensure consistent behavior in computations. Mathematically, rounding is often denoted as \round(x, d), where x is the number to round and d specifies the number of places or significant digits. For rounding to the nearest under the half-up rule, one common implementation is \lfloor x + 0.5 \rfloor; for example, with x = 3.7, adding 0.5 yields 4.2, and applying the floor function gives 4. This derivation highlights how combines truncation with an offset to achieve to the nearest value. Alternative notations include the nearest function nint(x) or , which selects the closest without specifying ties. The practice of numerical rounding traces back to ancient Babylonian mathematics, where the sexagesimal (base-60) system was employed for astronomical calculations, often involving approximations to manage irregular fractions and avoid cumbersome irregular numbers. Scribes in the Old Babylonian period (circa 2000–1600 BCE) routinely rounded values during practical computations, as evidenced in administrative and mathematical tablets, to streamline arithmetic in fields like land measurement and celestial predictions. In modern statistics, rounding serves to limit error propagation by matching the precision of results to that of the input data, preventing overstatement of accuracy. Rounding introduces potential errors, particularly and accumulation in iterative calculations. Directional methods like round half up can systematically results upward, as repeated applications favor higher values (e.g., rounding a series of 0.5 increments in financial computations may overestimate totals over time). In statistical analyses, using rounded data for variance estimation or can yield biased coefficients, with the degree of bias depending on the precision and data distribution. To mitigate accumulation, unbiased methods like round half to even are preferred in high- environments, such as , where errors can propagate exponentially in chained operations.

Round numbers

Round numbers are integers that terminate in one or more zeros or consist of simple, memorable digits, such as 10, 100, or , serving primarily as approximations in and communication. These numbers function as cognitive prototypes, facilitating quicker mental processing compared to irregular figures, as they align with basic principles in human cognition. In everyday usage, they simplify complex quantities, allowing individuals to convey rough magnitudes without precision, such as stating "about a hundred" instead of an exact count. Psychologically, round numbers benefit from cognitive , making them easier to encode, retrieve, and manipulate in the mind, which leads to preferences in and . This can enhance emotional responses; for instance, round figures like $10 are often perceived as more sincere or premium in contexts compared to $9.99, influencing evaluations toward feelings of quality or completeness. They also act as mental anchors for milestones, such as celebrating a 100th , providing psychological structure and by marking progress against reference points. However, this can introduce inaccuracies in estimations, as people gravitate toward them even when precise values are available, potentially reducing overall judgment accuracy. In applications, round numbers streamline statistical by rounding estimates to the nearest 10 or 100 for clarity in sampling and data presentation, avoiding unnecessary that could mislead interpretation. In , they aid budgeting by allocating funds in even increments, such as rounding monthly expenses to $50, which simplifies planning and creates buffers for variability. Everyday language relies on them for casual approximations, enhancing communication efficiency in non-technical discussions. Culturally, often symbolize and ; in traditions, multiples of 10 evoke wholeness due to the character's dual meaning of "round" (yuán) and fulfillment, influencing practices in for balanced environments. Historically, the ancient employed a base-20 , structuring their around "rounds" like the 52-year (18,980 days), which integrated 20-day periods with 13-day counts to denote temporal and significance.

Science and technology

Physical roundness

In physics, roundness often emerges as a configuration that minimizes in systems governed by and differences. For instance, soap bubbles adopt a spherical because this form minimizes the surface area for a given , thereby reducing the energy associated with the liquid-air . This is described by , which quantifies the difference across the curved surface of a bubble as \Delta P = \frac{2\sigma}{r}, where \sigma is the and r is the ; the ensures by balancing internal against forces. Natural phenomena frequently exhibit approximate roundness due to competing forces like , , and . Raindrops initially form spheres in the atmosphere because pulls water molecules into the shape that minimizes , while and counteract deformation until the drop grows large enough for aerodynamic forces to flatten it. Similarly, planetary orbits, as established by Kepler's first law, are elliptical with at one focus, but many—such as Earth's with an of about 0.017—are nearly circular and thus often approximated as round for simplicity in basic models, reflecting the near-spherical symmetry arising from gravitational dominance. In material science, roundness is quantified for particles, particularly in sediment analysis, to assess shape influences on and deposition. The sphericity index, introduced by Wadell, measures how closely a particle approximates a and is calculated as \phi = \frac{\pi^{1/3} (6 V_p)^{2/3}}{A_p}, where V_p is the particle volume and A_p is its surface area; values range from 0 (highly irregular) to 1 (perfect ), aiding in evaluating sedimentary processes like and velocity. This metric is widely applied in to classify clastic particles, where higher sphericity correlates with more rounded forms from prolonged . Historical discoveries have illuminated roundness in physical contexts. , in his 17th-century experiments on motion, used spherical cannonballs to study falling bodies and projectile trajectories, observing that their uniform roundness allowed consistent rolling on inclines and parabolic paths under , challenging Aristotelian views and laying groundwork for inertial principles. In the 20th century, advanced atomic models with rounded electron distributions; Schrödinger's 1926 wave equation revealed that the hydrogen atom's ground-state electron cloud exhibits spherical symmetry, representing a probability density rather than fixed orbits, which became foundational for understanding atomic structure.

Computing and engineering uses

In , floating-point arithmetic relies on to handle the limitations of representation, where the specifies four primary modes: round to nearest (with ties rounding to the nearest even number as the ), round toward positive , round toward negative , and round toward zero. These modes ensure predictable behavior in numerical computations, but errors arise because many values lack exact equivalents. For instance, the of 0.1 and 0.2 in double-precision floating-point yields approximately 0.30000000000000004 rather than exactly 0.3, due to the inexact approximations of 0.1 (stored as about 0.1000000000000000055511151231257827021181583404541015625) and 0.2. Such discrepancies can accumulate in iterative algorithms, affecting precision in applications like simulations and graphics rendering. In , roundness—defined as the deviation from in a cross-section—poses significant challenges for machined components, particularly in rotating parts where non-roundness leads to imbalance, , or failure. For , the tooth profile enables constant velocity ratio during meshing, but roundness tolerances on the bore, pitch circle, and outer diameter are critical to minimize ; standards like AGMA and ISO 1328 classify gear accuracy into grades (e.g., 0 to 12), with higher grades requiring roundness deviations under 5 μm for applications to ensure smooth operation and . In bearings, roundness errors in races and rolling elements must be tightly controlled, typically to deviations below 1 μm in high-speed or high-load scenarios, as even sub-micrometer imperfections can amplify vibrations and reduce lifespan by altering load distribution. Coordinate measuring machines (CMMs) address these challenges by probing multiple points on a cylindrical surface, fitting data to reference circles (e.g., via least-squares or minimum zone methods), and quantifying roundness as the difference between enclosing circles, achieving resolutions down to 0.1 μm for . Post-2010 standards like ISO 286-2 have enhanced specifications for fits and tolerances in rounded cylindrical features, defining tolerance grades (IT01 to IT18) and fundamental deviations for holes and shafts to ensure interchangeable assembly; for example, in interference fits for shafts up to 50 mm, roundness must often align with IT5-IT7 classes (around 2.5-9 μm) to prevent excessive play or binding. Recent developments since 2020 integrate AI-driven optimizations in to boost efficiency; the AdaRound technique, for post-training quantization of neural networks, adaptively adjusts weight based on task and input , reducing accuracy degradation by up to 20% compared to nearest-integer in models like ResNet on . In , approximations via the quantum approximate optimization (QAOA) employ strategies for variational parameters, with 2024 advancements in initialization (setting to multiples of π/8) improving approximation ratios for combinatorial problems like Max-Cut by enhancing convergence in multi-layer circuits on noisy intermediate-scale quantum hardware.

Music

Musical round

A musical round is a polyphonic form consisting of a canon in which multiple voices perform the same , entering sequentially at fixed time intervals while repeating the phrase indefinitely until all parts conclude. This strict creates overlapping layers that generate without additional melodic material. Unlike more complex canons, a round typically features exact replication at the or specified pitches, with all voices concluding simultaneously after completing the necessary repetitions to align the ending. The structure of a round usually involves three or four voices, each by a consistent rhythmic unit—such as one or two beats or measures—to produce interlocking . As the voices overlap, harmonies emerge from the simultaneous notes, often aligning with simple progressions like those built on triads. For instance, in a basic three-voice round, the first voice begins the , the second enters after a delay (e.g., four beats), and the third follows similarly, resulting in a continuous where the loops back seamlessly. Notationally, this appears as staggered entries of the same line, such as: 
Voice 1: [Melody](/page/Melody) starts at [beat](/page/Beat) 1
Voice 2: [Melody](/page/Melody) starts at [beat](/page/Beat) 5
Voice 3: [Melody](/page/Melody) starts at [beat](/page/Beat) 9
This arrangement ensures coherence, with transitional notes permitted only if they avoid dissonance. A well-known example is "," where three voices enter every four s, forming triadic harmonies through the repetition. Theoretically, rounds rely on the principle of , where each mirrors the leader's precisely after the offset, fostering a sense of . Intervals between entering voices are frequently perfect fifths or fourths to promote overlaps, drawing from early polyphonic practices that prioritized these "perfect consonances" for stability. This imitative technique highlights contrapuntal independence while maintaining , making rounds an accessible introduction to . Origins trace to medieval , evolving from 13th-century forms like the conductus and early canons, with the earliest surviving example being the English rota "" (c. 1250), a six-voice round notated in a manuscript from . Rounds gained popularity in 18th-century education through singing schools, where they served as practical exercises for teaching part-singing and to amateur groups.

Historical examples

One of the earliest surviving examples of a musical round is the medieval English canon "," dating to around 1250 and preserved in the British Library's Harley Manuscript 978. This six-part polyphonic work, composed in the dialect of , celebrates the arrival of spring with lyrics invoking the cuckoo's song and features four voices in the primary rota supported by a two-voice pes ground bass, marking it as the oldest complete secular polyphonic song in English. During the , the form gained wider dissemination through printed collections, with Thomas Ravenscroft's Pammelia (1609) serving as the first such anthology in . This volume compiled 100 rounds, canons, and catches, drawing from both sacred and secular traditions, and played a key role in popularizing the among amateur musicians and in social settings. Ravenscroft's work built on earlier traditions, adapting and notating pieces for three to six voices to facilitate group singing. In the modern era, "Frère Jacques" emerged as a prominent French round in the 18th century, originally titled "Frère Jacques, dormez-vous?" and structured for four voices in canon form. This nursery rhyme, depicting a sleepy monk ringing matins bells, spread internationally and became a staple in children's music education due to its simple melody and repetitive structure. By the 20th century, rounds like this were adapted in folk music revivals and pedagogical methods, such as Zoltán Kodály's approach to music education, which emphasized sequential singing of canons to develop pitch accuracy and ensemble skills in school choirs. Musical rounds have long held cultural significance in choral training, fostering part independence, rhythmic precision, and group cohesion among singers of all ages. While predominantly a form, analogs appear in non- traditions, such as call-and-response patterns, where overlapping vocal lines create similar polyphonic effects in communal .

Sports and games

Competition rounds

In combat sports, particularly and , a round refers to a , timed segment of the match designed to structure the competition, manage participant fatigue, and ensure safety. These rounds alternate with brief rest periods, allowing fighters to recover while preventing indefinite bouts that characterized earlier, unregulated forms of the sport. The concept evolved from bare-knuckle prizefights, which often lasted hours without time limits and carried high injury risks, to standardized formats that prioritize controlled engagement and medical oversight. In , each round typically lasts three minutes, followed by a one-minute break, with bouts scheduled for 4 to 12 rounds depending on the event's stakes—non-title fights often limited to 10 rounds and championships to 12. This structure was formalized by the , drafted in 1867 by John Graham Chambers and sponsored by John Sholto Douglas, the 9th Marquess of Queensberry, which introduced padded gloves, a roped , and timed rounds to replace bare-knuckle marathons. Scoring occurs per round, with judges awarding points based on effective striking, defense, and ring generalship, accumulating toward a decision if the fight goes the distance; a single round can decisively influence the outcome through knockouts or dominant performances. Other combat sports adapt similar phased formats for fatigue management and strategic pacing. In (MMA) under Unified Rules, rounds last five minutes with one-minute rests, typically three for non-title bouts and five for championships, enabling a blend of striking, , and submissions while allowing recovery to mitigate exhaustion. Wrestling matches, by contrast, use periods rather than rounds: international freestyle and Greco-Roman bouts consist of two three-minute periods with a 30-second break, while features a three-minute followed by two two-minute periods, emphasizing continuous action with if tied. These intervals help sustain intensity without overwhelming physical demands, reducing cumulative from prolonged exertion. The of rounds marked a pivotal shift for in Olympic boxing, introduced in with three three-minute rounds per bout—a format that persists today for both men and women, though women's events briefly used four two-minute rounds before standardizing to three by the 2020 Games. This evolution curtailed the dangers of unlimited fighting seen in 19th-century exhibitions. Statistically, matches rarely reach full duration; bouts average 17-22 minutes (roughly 5-7 rounds), while overall professional fights last about 25-30 minutes including breaks, with over 60% ending by stoppage before the final round. In UFC MMA, average fight times hover around 10-12 minutes, underscoring how rounds facilitate decisive conclusions amid escalating fatigue.

Game formats

In board, card, and team games, a round typically denotes a sequential stage or complete of play in which participants take turns or engage in structured interactions, often ending when all players have acted or a predefined condition is fulfilled, such as the exhaustion of available resources or the completion of a betting sequence. This format promotes fairness by ensuring equal participation opportunities while building tension through progressive decision-making across multiple rounds until a game concludes via scoring, elimination, or victory conditions. A classic example appears in dominoes variants like Draw Dominoes, where each round begins with players drawing from (stock) and matching tiles end-to-end; the round terminates when the boneyard depletes and no further plays are possible, with points awarded based on opponents' remaining tiles. In card games such as Texas Hold'em poker, rounds are divided into betting phases—preflop, flop, turn, and —where players wager chips after receiving community cards, aiming to form the best hand while managing and bluffing risks. Board games like structure play in implicit rounds, each comprising a full circuit where all players roll dice and act once, advancing around the board to acquire properties and collect rents until bankruptcies resolve the game. Round-robin formats, common in team-based strategic games, organize rounds so that every participant or team competes against all others in turn, fostering comprehensive matchups without early eliminations and originating in late-19th-century sports like lawn tennis before adapting to board game tournaments. Strategies in these round-based structures emphasize , such as allocating limited assets like chips, tiles, or action points per round to disrupt opponents or build advantages, often prioritizing defensive consolidation early and aggressive plays later. Variants include elimination rounds in chess tournaments, where players advance through paired matches in successive stages, with losers exiting until a emerges, contrasting single-round formats by extending over multiple encounters. This mirrors timed rounds in combat sports but focuses on non-physical, deliberative tactics rather than .

Social and economic contexts

Repeated social activities

In social settings, a refers to the practice where participants in a group take turns purchasing beverages for everyone, typically in bars or , to foster equality and camaraderie. This custom emerged prominently in 19th-century , where served as central hubs for working-class social interaction, allowing individuals to share the responsibility of bar visits and ensure fair contribution to group expenses. dictates that no one skips their turn—known as "dodging the round"—as doing so can lead to , and purchases are ideally made when glasses are about half-empty to maintain flow. The practice promotes social bonding by reinforcing reciprocity, akin to gift-giving rituals that reduce tension and affirm group membership, particularly among men in traditional pub environments. Cultural variations of drink rounds appear in several regions, adapting to local norms while preserving the sequential buying principle. In and , rounds are a cornerstone of pub etiquette, with participants announcing "it's my round" to signal their turn and often limiting group size to 3-4 for practicality. During in , rounds faced temporary legal bans under schemes like the State Management Scheme to curb wartime overconsumption, highlighting their perceived role in social excess yet underscoring their enduring value for community cohesion. Beyond drinks, repeated social activities structured in rounds include collaborative , where group members contribute sequentially to build a , often around campfires or in casual gatherings. In these , each participant adds a or phrase in turn, encouraging creativity and listening while strengthening interpersonal connections through shared imagination. This format, popular in outdoor settings like events or family outings, traces to traditional circles that promote inclusivity without competition. Post-2020, amid the , these practices adapted to virtual formats in online meetups, where participants simulate rounds by coordinating drink orders or toasts via video platforms like during remote happy hours. This evolution maintained the relational essence of rounds, allowing dispersed groups to sustain bonding rituals despite physical separation.

Business and funding

In the context of startups and emerging companies, rounds represent structured stages of raising that enable growth from ideation to leadership. These typically begin with pre-seed and rounds, where early —often from investors, friends, family, or accelerators—validates the business concept and supports initial product , with investments typically ranging from $500,000 to $5 million at pre-money valuations of around $5 million to $20 million (median $16 million as of Q1 2025). Subsequent Series A rounds focus on achieving and scaling operations, attracting (VC) firms with investments of $10 million to $25 million at post-money valuations of $40 million to $150 million (median around $60 million as of Q2 2025). Series B and C rounds build on proven traction, expansion and team growth, with larger sums—$30 million to $100 million or more—and valuations often exceeding $100 million, sometimes leading to status (a $1 billion valuation) by Series D or later. For instance, the probability of reaching status rises dramatically across rounds, from about 0.5% at to over 30% by Series H. The funding process involves founders pitching their business via detailed decks to VC firms, highlighting market opportunity, traction, and financial projections to secure interest. If compelling, VCs issue a non-binding outlining key terms such as investment amount, pre- and , equity stake, liquidation preferences, and anti-dilution protections, which serves as a blueprint for legal agreements. follows, verifying claims through financial audits and reference checks, before closing the round with share issuance. A notable example is Uber's 2011 Series B round, where it raised $37 million led by Menlo Ventures, with participation from and , at a valuation that propelled its early expansion into multiple cities. Beyond traditional , product development often proceeds in iterative rounds of testing and refinement, akin to agile methodologies, where startups conduct cycles of prototyping, user feedback, and adjustments to minimize risks and align with market needs—typically spanning weeks to months per iteration. In the sector, rounds have evolved post-2020 to include (DAO) models, where community-governed entities like VitaDAO pool tokens for investments in projects, such as research initiatives raising millions through token sales and votes. Economically, each round introduces dilution, reducing founders' and early investors' ownership percentages—for example, a 20% stake in a seed round might drop to 10% after Series A due to new share issuance—but this is often offset by rising company valuations that increase absolute share value. Strategic of dilution through option pools and ensures long-term among stakeholders.

Places

Geographical features

Round valleys represent notable examples of circular or near-circular topographic depressions formed through distinct geological processes. In , Round Valley in Mendocino County is a tectonic characterized as a down-faulted block bounded by faults, resulting from in the Coast Ranges. Similarly, Round Valley in , located within the , forms a U-shaped depression enclosed by the resistant diabase ridges of Cushetunk Mountain, a intrusion that resisted while surrounding softer sedimentary rocks were removed, creating the valley's rounded outline. Round hills, often manifested as domed , are isolated, steep-sided elevations rising from surrounding plains due to differential of harder rock masses. These features, such as bornhardts formed from or , exhibit smooth, curved domes shaped by exfoliation and processes that peel away outer layers, leaving a rounded core. Circular lakes can arise from impacts, as seen in India's Lonar Crater, a 1.8-kilometer-wide in Deccan formed approximately 50,000 years ago by a impact, which ejected material and created a near-perfect circular depression now occupied by a saline lake. Geological processes contributing to round features include volcanic activity and erosion. Volcanic calderas often develop circular shapes through the collapse of the magma chamber roof following large eruptions, as the subsidence occurs symmetrically around the vent due to the removal of underlying support. Erosion, meanwhile, can round landforms via prolonged weathering and fluvial action, with the degree of circularity quantified using the circularity index, defined as the ratio of a feature's area to the area of a circle with the same perimeter (approaching 1 for perfect circles), applied to depressions like sinkholes or basins to assess shape regularity. In , rounded river bends, known as meanders, play a key ecological role by moderating , promoting deposition, and creating diverse habitats such as lakes and riparian zones that support in ecosystems. These natural formations occasionally influence nearby human settlements by providing fertile, enclosed basins for and water storage.

Settlements and structures

Round Lake Beach, Illinois, emerged as a resort community in the late 19th and early 20th centuries, capitalizing on the recreational appeal of Round Lake following the arrival of the , and St. Railroad in 1901, which established the area's reputation as a destination. The village was formally incorporated in 1937 after developer L.B. Harris subdivided land along the lake's west shore in 1930, marketing affordable summer cottages to workers during the . Round Rock, Texas, is a city named for a distinctive round boulder in Brushy Creek that served as a landmark for travelers and a point in the mid-19th century. Originally settled in the 1830s and known as Brushy Creek, the community was renamed Round Rock in 1854 when applying for a post office, honoring the prominent limestone formation that guided wagons and marked the ford. Round houses have been constructed worldwide for their structural advantages, including enhanced wind resistance due to their aerodynamic form. In , traditional rondavels—circular huts made from mud, stone, or wood with thatched roofs—exemplify this design, allowing winds to flow around the structure rather than against flat walls, which is particularly beneficial in regions prone to high winds. Historically, in , , features a circular arrangement of massive stones erected between 2600 and 2400 BCE, forming a prehistoric monument with a of about 30 meters that aligns with astronomical events. In modern infrastructure, roundabouts serve as efficient circular traffic structures to manage flow and reduce congestion. in , , constructed in 1972, consists of five mini-roundabouts encircling a central anti-clockwise one, handling thousands of vehicles daily while minimizing accidents through its unconventional design. Post-2015 sustainable architecture has increasingly incorporated round forms aligned with principles, emphasizing material reuse and energy efficiency; for instance, in , completed in 2017, is a massive circular office building powered by via on-site solar panels and fuel cells, achieving Platinum certification as North America's largest such structure. Indigenous round dwellings often embody cultural symbolism of community and interconnectedness. Among many Native American groups, such as the Plains tribes' tipis, the circular layout represents the of all participants in a , mirroring natural cycles and fostering communal living without hierarchical corners.

Other uses

Ammunition and tools

In firearms, a "round" refers to a single complete unit of , consisting of a case, primer, powder, and , such as a or . The case serves as the container that holds the other components together, typically made of , , or for durability and reliable feeding into the . The primer is a small, impact-sensitive that ignites the powder charge when struck by the , while the powder burns rapidly to generate the gas pressure that propels the down the barrel. For example, a .50 round is a large-bore used in heavy machine guns, featuring a robust case and a heavy lead-core often jacketed for penetration. Military applications emphasize standardized rounds designed for reliability and compliance with , such as (FMJ) , where the bullet's lead core is fully encased in a harder metal like to prevent excessive expansion upon impact. FMJ rounds, like the 5.56mm NATO cartridge, are the standard for rifles because they adhere to the Hague Convention's on expanding bullets in warfare, ensuring they pass through targets without fragmenting and causing unnecessary suffering. This design also facilitates high-volume feeding in automatic weapons, making it suitable for sustained combat operations. The history of ammunition rounds traces back to the 15th and 16th centuries, when early firearms like used loose spherical lead balls—known as musket balls—loaded with separate black powder charges, requiring manual ramming for each shot. By the , the development of self-contained metallic cartridges revolutionized firearms, integrating all components into a single unit for faster reloading; this culminated in modern rimfire and centerfire rounds, such as the 5.56mm standard adopted in the for its balance of lightweight design and . Global production of ammunition runs into billions of rounds annually, with estimates varying widely; for example, U.S. production alone exceeds 12 billion rounds per year as of 2023 data. Safety considerations for include low misfire rates, where a round fails to ignite due to primer defects or flaws; high-quality modern primers achieve reliability rates of 99.9997%, meaning a misfire might occur only once every 300,000 rounds under normal conditions. Proper storage in cool, dry environments minimizes degradation, reducing risks during repeated firing sequences akin to those in or competition. Beyond ammunition, "round" describes certain hand tools used for shaping and finishing materials. A round file is a cylindrical with abrasive teeth along its length, tapered to a point, designed for enlarging or smoothing circular holes and internal curves in wood, metal, or . These files, often available in bastard or smooth cuts for coarse or fine work, are essential in for deburring rounded edges or filing concave surfaces. Similarly, round-shank drill bits feature a straight, cylindrical that fits standard three-jaw chucks in handheld s, allowing precise boring of holes in wood, metal, and composites. High-speed steel versions with black oxide coatings provide enhanced durability and heat resistance for prolonged use.

Cultural and symbolic meanings

In various cultural and philosophical traditions, the round shape symbolizes wholeness, unity, and the cyclical nature of existence. The , an ancient symbol depicting a devouring its own tail, represents eternal renewal and the infinite cycle of life, death, and rebirth, originating in Egyptian iconography around 1600 BCE and later influencing alchemical thought. This motif aligns with philosophical concepts like the , as articulated by , where events recur endlessly, emphasizing the circularity of time and cosmic order. In art and spiritual practices, round forms such as mandalas—circular diagrams with symmetrical patterns—serve as tools for meditation, embodying the universe's interconnectedness and promoting inner harmony in Buddhist and Hindu traditions. In literature, the round table from Arthurian legend exemplifies equality and democratic fellowship among knights. Introduced in the 12th-century romance Roman de Brut by Wace, the table's circular design eliminates hierarchy by providing no head seat, symbolizing chivalric unity under King Arthur. Idiomatic expressions like "go the rounds" also draw on roundness to denote circulation, originating in the 19th century to describe stories or rumors spreading from person to person, evoking a path that loops through a community. Culturally, round motifs appear in performative and festive contexts to evoke continuity and communal bonds. The , practiced by tribes such as the and , uses circular hoops to represent the eternal cycle of life, seasons, and interconnectedness, with dancers weaving them into forms symbolizing animals and renewal during healing ceremonies. Similarly, round lanterns during and the embody wholeness and family unity, their spherical shape mirroring the and signifying , good fortune, and the rejection of past misfortunes as they float away. Global symbolism extends to , where geometric patterns incorporating circles and rosettes—dating back to the —denote divine unity and the infinite nature of creation, as seen in intricate tilework of mosques like the , avoiding figurative imagery to focus on abstract harmony. These motifs, evolving from the onward, reflect the circle as a emblem of the , bridging , , and across diverse civilizations.