Divide the width of the shelf by the widthof the books.
First rewrite feet as inches:
1 foot = 12 inches.
3 1/2 feet x 12 inches per foot = 42 inches
Now divide the width of the shelf by the width of the book:
Now you have 42 / 5/8
When dividing by a fraction flip the second fraction over and change division to multiplication:
42 x 8/5
Now Multiply across:
7/2 x 8/5 = (42 x 8) /5 = 336/5 = 67.2
Round to the nearest whole number: 67
The shelf will hold 67 books.
