7 divided by 10 is .70
So 7/10 is 70%
To convert a fraction to a percentage, devide the numerator (top) by the denominator (bottom) and make your first 2 decimals your percentage.
So to find 1/3 as a percentage, divide 1 by 3 to get .33333334, then take the first 2 numbers, in this case, .33 and make them your percent, 33%