Skill: Order containers by capacity

Capacity means how much a container can hold. A tall container does not always hold more than a short, wide container.

To compare containers:

1. Fill each container all the way to the top.
2. Pour the liquid from each container into the same clear tub.
3. Look at the water levels.
4. The container that makes the highest water level has the greatest capacity.

Example

There are three containers:

• Container A: a tall, skinny jar
• Container B: a short, wide bowl
• Container C: a small cup

Fill each one to the top. Pour each full container into the same tub and mark the water levels.

• The water from B reaches the highest mark.
• The water from A reaches the middle mark.
• The water from C reaches the lowest mark.

So, from least capacity to greatest capacity:

$$C,\ A,\ B$$

Container A is taller than B, but B holds more. This shows that a container’s shape and height do not always tell us its capacity.