A carpenter has a board that is 8 feet long. he cuts off two pieces. one piece is 31/2 Feet long and the other is 21/3 Feet long. how much of the board is left

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, 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.