Definition of fraction in US English:



  • 1A numerical quantity that is not a whole number (e.g. 1/2, 0.5).

    • ‘To convert a fraction to a percentage, divide the numerator by the denominator.’
    • ‘The math course consists of five subject areas: understanding numbers, using whole numbers, using decimals, using fractions and per cents, and working with data.’
    • ‘Use the method above to convert it into a fraction with whole numbers in the denominator.’
    • ‘The Mathematics Computation subtest assesses skills in computing with whole numbers, fractions, mixed numbers, decimals, and algebraic equations.’
    • ‘You may have to multiply both fractions by different numbers to produce the same denominator for both fractions.’
    • ‘What are the rules for converting fractions to binary and octal and vice versa?’
    • ‘Sometimes when working with fractions, the hardest thing to find is a common denominator.’
    • ‘These most rarely occurring topics were: angles in a quadrilateral, fractions, fraction multiplication, properties of triangles, and the Pythagorean theorem.’
    • ‘Possibly as a consequence of that, the Greek mathematicians thought of fractions in terms of ratios of integers, rather than numbers.’
    • ‘In other words, a number is rational if we can write it as a fraction where the numerator and denominator are both integers.’
    • ‘Column addition was performed on whole numbers and then on fractions.’
    • ‘It looks first at area problems, then looks at rules for the addition, subtraction, multiplication and division of fractions.’
    • ‘They should also be able to understand basic maths and geometry, including fractions, decimals, multiplication and division.’
    • ‘Specifically, children's responses to the less familiar quantities of zero and fractions could shed light on their performance with the more familiar whole numbers.’
    • ‘Basic operations with whole numbers, fractions, and decimals were required to solve some problems, although many items required no calculations.’
    • ‘The line between the numerator and denominator is known as the fraction bar.’
    • ‘Although all these fractions are written differently, they all represent the same quantity.’
    • ‘Students added several combinations of wood in whole numbers and mixed fractions as they tested the most economical ways to use the lumber.’
    • ‘The aim of the first part is to introduce the Hindu numerals, to explain a place value system and to describe addition, multiplication and other arithmetic operations on integers and fractions in both decimal and sexagesimal notation.’
    • ‘Others would rewrite the fractions using common denominators.’
  • 2A small or tiny part, amount, or proportion of something.

    ‘he hesitated for a fraction of a second’
    ‘her eyes widened a fraction’
    • ‘Each of those putative atoms of element 115 disintegrated within fractions of a second by spontaneously ejecting an alpha particle, which contains two protons and two neutrons.’
    • ‘Turns out that he produces some rather wonderful music consisting almost entirely of samples, usually only a fraction of a second long.’
    • ‘They had acquired the land for a tiny fraction of that amount.’
    • ‘The council currently spends a fraction of this amount on all its other roads combined.’
    • ‘No one would ever notice a fraction of a cent but with the amount of financial transactions going on those fractions mounted up.’
    • ‘The victim would be left with only £5,000-a fraction of the amount intended to cover his pain and suffering.’
    • ‘It's only a fraction of the amount of money necessary to attend most private schools.’
    • ‘Only a fraction of the huge amount of money we pay in road taxes is put into the maintenance and building of roads.’
    • ‘He said hundreds of lives could be saved on the roads every year for a fraction of the amount being spent on rail safety.’
    • ‘The new process allowed mass production using a fraction of the amount of silver thereby reducing costs.’
    • ‘Her goal was $60,000 but she was only able to get a fraction of that amount.’
    • ‘Joule also invented extremely precise thermometers, which could measure temperature changes to within fractions of a degree Fahrenheit.’
    • ‘The parasitic wasp is quite tiny, only a fraction of the size of an adult fly.’
    • ‘However, the true cost is a fraction of this amount.’
    • ‘In this way hundreds of small adjustments can be made in a fraction of the time needed by more traditional methods.’
    • ‘If they did, the insurance company would have been charged a fraction of that amount.’
    • ‘In terms of proportion, only a fraction of local cotton is transformed and exported as finished goods.’
    • ‘Fortunately, a salvage unit was available, at a fraction of that amount.’
    • ‘That amount was only a fraction of the true value of the business, according to farmers of the former co-op.’
    • ‘Her eyes rest on me for a second, and I swear I can see a tiny ghost of a smile for a fraction of a second.’
    tiny part, small part, fragment, snippet, snatch, smattering, selection
    tiny amount, little, bit, touch, hint, soupçon, trifle, mite, scrap, dash, spot, modicum, shade, jot
    View synonyms
    1. 2.1 A dissenting group within a larger one.
      • ‘These shifts did not occur without inner turmoil and conflict, and many fractions continue to struggle within the party today.’
      • ‘Most relevant to this essay is Bourdieu's idea of social class fractions that depend on the composition of their three capitals, cultural, social, and economic.’
      • ‘I think they are likely to lead to conflicts between fragments and fractions within ruling corporate elites.’
      • ‘Fundamentalism attracts different class fractions across cultural locales in a common struggle against a diminishing or diminished social status, influence, and power.’
      • ‘The state, then, is the condensation of a hegemonic relationship between dominant classes and class fractions.’
      • ‘On the other hand, we can see very clearly the fractions within the hardliner camp, again in contrast to what the pro-participation group is saying.’
      • ‘It is more than simply a political alliance between social forces represented by classes or fractions of classes.’
      • ‘Revisionists distinguished between fractions of the ruling class in a significant way.’
      • ‘Class fractions are a fundamental feature of corporate capitalism and can become particularly potent fault lines.’
      • ‘The Greens have their pro and anti-capitalist fractions and are working though the issue.’
      • ‘The lower middle class experiences deprivation relative to the new middle class fractions above them in terms of wealth, power, and prestige.’
      • ‘Today's Muslim is put under the spotlight and has been critically scrutinized not only by the non-Muslim communities' worldwide but also from fractions within our own community.’
      • ‘The following year a follow up album was released, Time and a Word, by which time fractions were beginning to open up within the ranks of the band as the battle for leadership started.’
      • ‘For those unversed in the fractions and factions of Labour local politics, here is a glossary.’
  • 3Chemistry
    Each of the portions into which a mixture may be separated by a process in which the individual components behave differently according to their physical properties.

    • ‘Soluble and insoluble fractions were separated by centrifugation at 8 000 g for 30 min at the extraction temperature.’
    • ‘Cells were collected 48 hr later, and nuclear and cytoplastic fractions were separated.’
    • ‘Oil refining separates the various fractions of petroleum by a process called fractional distillation and takes place in a large plant called a refinery.’
    • ‘This is a generic term for the light hydrocarbon fractions found associated with most oil deposits.’
    • ‘Total lipid extracts were separated into neutral and polar lipid fractions by column chromatography on Florisil 60-100 mesh.’
    • ‘Of course, there is some overlap of the boiling points and molecular size for these fractions.’
    • ‘The cell lysate was then centrifuged at 27 000 g for 30 min at 4°C and the soluble and insoluble fractions were separated through a syringe.’
    • ‘The acetone and methanol fractions were combined and dried under nitrogen.’
    • ‘Both are produced by refining crude oil, but the kerosene fraction of the oil is a little heavier.’
    • ‘The resulting soluble organic fractions were analysed for polynuclear aromatic compounds and tested for mutagenic effects.’
    • ‘The ethyl acetate of the combined organic fractions was evaporated under reduced pressure.’
    • ‘The supernatant and the precipitate fractions were separated.’
    • ‘The aqueous, ethanol and ethyl acetate fractions were slowly evaporated to dryness under vacuum and stored at 4 degreesC for biological study.’
    • ‘The majority of the manufacturing is from the catalytic cracking of ethane, petroleum fractions, and crude oil.’
    • ‘The gum arabic fractions were collected separately and extracted with water/chloroform.’
    • ‘Benzene is manufactured industrially by dehydrogenation and dealkylation of appropriate fractions of petroleum.’
    • ‘After incubation, the samples were treated as above, and the supernatant fractions were lyophilized.’
  • 4usually the Fraction(in the Christian Church) the breaking of the Eucharistic bread.


Late Middle English: via Old French from ecclesiastical Latin fractio(n-) ‘breaking (bread)’, from Latin frangere ‘to break’.