
On a farm, apples are sold by both the bushel and part of a bushel. If there were 2 full bushels and a customer wanted only half a bushel, the farmer would break one of the bushels into halves and sell the customer the half bushel. The farmer would then have one and a half bushels remaining. 
Borrow from the whole number when needed. Convert the ONE that was borrowed into an equivalent fraction with the same denominator as the fraction doing the subtracting. If a there is already a fraction attached to the number, add the ONE onto it. 

Maggie has 3 1/2 bushels of apples. Melvin wants to buy 1 5/8 bushels. 



She can easily give Melvin 1 4/8. 



She can give Melvin one of the 8ths. She is left with 1 7/8 bushels. 