math
posted by leslie on .
how do i find 1/3 of 9
2/5 of 25

in math, the word of means times so you would multiply 1/3 x 9 & 2/5 x 25. To set these problems up, you would change the whole numbers (9 & 25) into fractions, so you would have 1/3 x 9/1 for the first one, and 2/5 x 25/1 for the second one. When you line them up on your paper, you can either multiply straight across the tops & the bottoms then reduce, or you can crosscancel before you multiply. Have you done crosscanceling?

You actually don't need to do all of the work Jesse has said. I'll show you a shortcut. Take the denominator (bottom part of a fraction) and divide it by your whole number. Then multiply that by the numerator (top part of a fraction). You can do it really fast in your head.
1/3 of 9 = 9/3=3x1=3
2/5 of 25= 25/5=5x2=10 
Take the denominator (bottom part of a fraction) and divide your whole number by it. Then multiply that by the numerator (top part of a fraction).