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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.

2 divided by 3 equals 10 divided by 153 divided by 5 equals 9 divided by 1510 divided by 15 is bigger than 9 divided by 152 divided by 3 is bigger than 3 divided by 5

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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