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Examples:
Note the use of words such as "times", "parts", "number", etc. This occurs because ratios are unitless; the units cancel out of the ratio. e.g. 3 kg /5 kg = 3 000 g. /5 000 g = 3/5.
Ratios are not exactly the same thing as fractionIn common usage a fraction is any part of a unit. In mathematics: A vulgar fraction is a rational number written as one integer (the numerator divided by a non-zero integer (the denominator . The line that separates the numerator and the denominator is cas. For example, if I have three penniesA penny (pl. pence or pennies is a unit of currency or a coin used in several English-speaking countries: 1/100 of the British Pound Sterling or the Irish pound ( 1971- 2001), or a coin with that value: see history of the English penny. 1/240 of the Briti and five nickelThe United States five cent coin commonly called a nickel is a unit of currency equaling one 1/20th of a United States dollar. Nickels are 21. 21 mm in diameter, 1. 95 mm thick, with a plain edge. With the exception of a period during World War II, nickels, then the ratio of pennies to nickels is 3:5 or 3/5 (this indicates that there are three fifths as many pennies as nickels, but the fraction of coins which are pennies is 3/(3+5) = 3/8 (this indicates that the chances of a randomly selected coinThis article is about monetary coins. For alternative meaning see see word coinage. euro coin A coin is generally a piece of hard material, traditionally metal and usually in the shape of a disc, which is used as a form of money. With banknotes, coins mak being a penny are three in eight).
The most common thing to do with ratios is multiply them. For example, if there are two snorts for every giggle, and three giggles for every guffaw, then (since 2sn/1gig × 3gig/guf = 6sn/guf) there are six snorts for every guffaw. Note that the intermediate unit "giggle" canceled out of the expression. Note also that each fraction in the expression was equal to one, which is how we know that their product (6sn/guf) is also equal to one. Similarly, if I know there are two guffaws, then I can multiply by 6 snorts per guffaw (6sn/guf = one, the multiplicative identity) to learn that there are 12 snorts.
Ratio equality is expressed with :: for example:
2:3::4:xwould imply x=6.