How many square decimeter boards does a carpenter need to make a cubic uncovered wooden box with a side length of 5 decimeters? If the thickness of the board is 2 cm, what is the volume of this wooden box?

Solution: A cubic wooden box with a side length of 5 decimeters has five sides, each of which is

A square with a side length of 5 decimeters,

∴ Use at least 5*(5*5)= 125 square decimeter board.

If the thickness of the plate is 2 cm =0.2 decimeter,

The square side length of the wooden box bottom is 5-2*0.2=4.6 decimeters.

The height in the wooden box is 5-0.2=4.8 decimeters.

The volume of this wooden box is 4.6 * 4.6 * 4.8 =101.57 cubic decimeter.