A carpenter has a board that is 8 feet long. He cuts off two pieces. One piece is 3 1/2 feet long and the other is 2 1/3 feet long. How much of the board is left?

First, add the two measurements up, then subtract it from 8.

3 1/2 + 2 1/3

Convert to improper fractions:

7/2 + 7/3

Convert to denominators of 6:

21/6 + 14/6

Add the numerators:

35/6

Subtract from 8:

8 - 35/6

Convert 8 into a denominator of 6:

48/6 - 35/6

Subtract the numerators:

13/6

Convert to a mixed number:

2 1/6

So 2 1/6 of the board is left.

First all fractions must have the same denominators 1/2 = 3/6 1/3 = 2/6 3 3/6+2 2/6 = 5 5/6 cut off pieces 8-5 5/6 = 2 1/6