① A cuboid bunker, 5m long, 3m wide and 0.5m deep. How many square meters is this bunker? If the bunker is full of sand, how many cubic meters of sand do you need?

Solution: cuboid volume = length x width x height =5x3x0.5=7.5m?

② The bottom of the container is square with a side length of 1.2dm, and the water level in the container is 0.8dm high. After putting stones (completely submerged), the water level in the container is 1dm. So what is the volume of the stone put in?

Solution: The rising volume of water =1.2x1.2x (1-0.8) = 0.288 cubic decimeter.

The volume of water rising is the volume of stone.