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 Subject: common denominator Who are you: Parent what is the common denominator of 3/5, 2/7 and 4/8?

Hello there.

There are many common denominators that you can use. The easiest way to find a common denominator is to multiply the denominators together. In your question, that would be 5 x 7 x 8 = 280. That's not the
lowest common denominator though. This question is likely trying to show you that you should reduce your fractions as much as possible before trying to find a common denominator. What is 4/8 equal to? it is 1/2. So replace it and then try to find a common denominator of 3/5, 2/7 and 1/2. Then you don't have to deal with such large numbers as 280.

Hope this helps,
Stephen La Rocque.

Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.