Question

A gallon jug of milk 3/4. After breakfast the jug 1/12 full. Find the difference of amounts before breakfast and after breakfast

Answer 1

You'll need to subtract 1/12 from 3/4.  Seeing that 12 is the LCD, convert 3/4 to 9/12.  Subtracting 1/12 from 9/12 results in 8/12, or 2/3 gallon (the amount of milk left after breakfast).