Ben had 2 boxes of blocks.

• Each box had 100 blocks.

• He built a tower with 1/5 of the blocks out of each of the boxes.

How many blocks did Ben use to build the tower?

Each box had 100 blocks in it.

- - 1/5 of the blocks in one box = 100/5 = 20 blocks.

- - 1/5 of the blocks in the other box = 100/5 = 20 blocks.

- - Total number of blocks used = (20 + 20) = 40 blocks.