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# Comparing fractions

To compare fractions, you must first change them so they have the same denominator.

Compare 2/3 and 3/5 and find out which fraction is bigger.

• First look at the denominators (the bottom numbers).

• Find a new number that both denominators go into:

• Try 9 - you can divide 9 by 3 but you can't divide 9 by 5.

• Try 10 - you can divide 10 by 5 but not by 3, so that isn't right either.

• Try 15 - you can divide 15 by 5 (which equals 3) and you can also divide 15 by 3 (which equals 5), so 15 is the new denominator.

• Now you have found a new denominator that is divisable by both numbers, you need to change the numerators (the top numbers).

• To change the numerators, simply multiply them by the number of times the denominator goes into 15.

• So for 2/3 - 3 goes into 15 five times, so you must multiply the numerator (2) by 5 which equals 10.

• And for 3/5 - 5 goes into 15 three times, so you must multiply the numerator (3) by 3 which equals 9.

So now both fractions have been changed you can compare them to see which fraction is the biggest. 10/15 is bigger than 9/15 so the biggest original fraction is 2/3.

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