# Computing Volume Progression 4

Alignments to Content Standards: 6.G.A.2

A rectangular tank is $24\text{ cm}$ wide, and $30\text{ cm}$ long. It contains a stone and is filled with water to a height of $8\text{ cm}$. When Amy pulls the stone out of the tank, the height of the water drops to $6\text{ cm}$. Find the volume of the stone.
The change in water height is $8 \text{ cm} – 6\text{ cm} = 2\text{ cm}$. The volume of the displaced water is the product of the length, width, and change in the height of the water, and $24 \times 30 \times 2 = 1440$.
The volume of the stone is the same as the volume of the displaced water, we know the stone has volume $1440\text{ cm} ^3$.