text: the difference between 3/4 and 1/3?   get a common denominator first -- since you have 3 and 4 in your denominators, use 3*4 = 12 for your common denominator:  multiply 3/4 * 3/3 to get 9/12. multiply 1/3 by 4/4 to get 4/2.  now 3/4 - 1/3 = 9/12 - 4/12 = 5/12.