Sample Problem: 4 7/8 - 1 3/5.
Step One: Find LCD. The LCD of 8 and 5 is 40.
Step Two: Convert fractions. Change 7/8 to 35/40 and change 3/5 to 24/40.
Step Three: Subtract whole numbers. 4 35/40 - 1 24/40 = 3 + ( 35/40 - 24/40 ).
Step Four: Subtract the fractions. 3 + 11/40.
Step Five: Reduce the fraction (if necessary) 3 11/40.
ANSWER: 3 11/40.