Lesson 12 — Activity 3:

Capacity


Now that you have looked at length and mass, the last metric measurement you will learn about is capacity (or volume).

Capacity is the amount of weight a container can hold. Another unit that is associated with capacity is volume. Volume is how much space an object takes up. In this lesson, you will focus on capacity.

Volume is how much space something takes up and capacity is how much something can hold. For example, a brick has volume because it takes up space, but it has not capacity. A cup has volume because it takes up space, and it has capacity because it can hold things.


Capacity

Here are some examples of capacity that you see every day!


Image Source: Unsplash

Image Source: Unsplash

Measuring capacity in the metric system is very similar to measuring length or mass. The prefixes remain the same and you move between the units the same way.

The main difference between capacity and mass or length is that you only use two of the units when you talk about capacity in everyday situations — litre (L) and millilitre (mL).




The two main units that you will use are the litre (L), which is the basic unit on this chart and the smallest unit, the millilitre (mL). To use this chart, you can use the same method as you did in the last two lessons:


OR, you can use the method below.

To convert millilitres (mL) to litres (L), you would divide by 1,000.


To convert litres (L) to millilitres (mL), you would multiply by 1,000.


     

You try it! Use the charts above to find the amounts.


How many litres (L) are in 5,000 millilitres (mL)?

How many millilitres (mL) are in 40 litres (L)?

40,000 millilitres (mL)

When working with capacity at school, at work, at home, or in your community, it is important that you choose the appropriate unit of measure. For example, when buying milk at the store, it is easier to think of buying 1 litre of milk rather than 1,000 millilitres of milk!

Let's practise choosing the appropriate capacity for various items.

For example, which is the best metric unit to use to show drivers the price of gas?

  • millilitres (mL)
  • litres (L)

The most appropriate unit would be litres (L)!


Image Source: Pixabay 

Image Source: Pixabay

A recipe for soup requires the amount of stock shown in the jug. The amount of stock needed for the soup is best written in which unit?

  • millilitres (mL)
  • litres (L)

The most appropriate unit would be millilitres (mL)!

Which is the best metric unit for measuring the capacity of a ladle?

  • millilitres (mL)
  • litres (L)

The most appropriate unit would be millilitres (mL)!

Image Source: Unsplash


Image Source: Unsplash

Jack wants to estimate the amount of water in the tub. Which is the best metric unit that Jack should use?

  • millilitres (mL)
  • litres (L)

The most appropriate unit would be litres (L)!

Remember!

To measure an object that has a small capacity,

use millilitres.

To measure an object that has a larger capacity, use litres.



  Self-check!

Try This!

Answer the questions below on your own first. When you are finished, click on the tabs below to check your answers!


Using the conversion charts in this lesson, find the amounts of the following:


3 L = _____ mL
5,000 mL = _____ L

25 mL = _____ L


3 L = 3,000 mL
5,000 mL = 5 L
25 mL = 0.025 L


Which is the best metric unit for measuring the amount of fuel in a truck's tank?


Image Source: Pixabay 


Click on the Play button below to watch a video on the difference between volume and capacity.