30/45
What numbers multiply to equal 30,and 45?
30: 1*30 ,2*15, 3*10, 5*6,
45: 1*45, 3*15, 5*9,
Look for the LARGEST number that they have in common.
15 is the largest number they have in common! Replace those multiplications with the numbers... like a so:
30/45 = (2*15)/(3*15)
The 15's will cancel out of the problem leaving us with the simplest form of the fraction.
2/3!