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LESSON 20: CAPACITY/VOLUME
In Grade 3 you learnt how to take measurements by pouring liquids into cups or measuring jugs and then reading the volume of liquid in them.
What is the difference between capacity and volume?
Your facilitator will show you two videos that will explain the difference between capacity and volume. • goo.gl/U3VL7n • goo.gl/jgWhHG
Can you write down in your own words what the difference is between capacity and volume?
Capacity is how much space an object has inside.
OR
Capacity is the amount a container or something can hold when filled.
Volume is the amount of space an object takes up.
An example of the difference between capacity and volume:
A glass can hold 250 mℓ of milk. You only pour 200 mℓ in the glass. In this example, the glass’s capacity is 250 mℓ and the volume is 200 mℓ.
Volume Capacity
In lesson 13 we looked at which units are used to measure length. Capacity and volume are also measured in specific units.
Capacity and volume are measured in: • millilitres (mℓ) • litres (ℓ)
Examples of measuring instruments used to measure capacity and volume.
Measuring spoons Measuring cups Measuring jugs
Study the objects below. In what unit would you measure the capacity and volume of each object?
Decide between millilitres (mℓ) and litres (ℓ).
Litre is a larger unit than millilitre. 1 ℓ is 1000 times more than 1 mℓ.
1 litre = 1 000 millilitres
You will measure the capacity and volume of larger objects in litres and to measure the capacity and volume of smaller objects in millilitres.
How do you convert between litres and millilitres?
× 1 000 litres (ℓ) millilitres (mℓ)
÷ 1 000
Examples of conversion
1. 3,2 ℓ = ____________ mℓ To convert litres to millilitres, you must multiply by 1 000. 3,2 × 1000 = 3200 mℓ
2. 8952 mℓ = ____________ ℓ To convert from millilitres to litres, you must divide by 1 000. 8952 ÷ 1000 = 8,952 ℓ
The number of zeros in 10, 100 and 1 000 show the total number of place values, which will have an influence when you multiply or divide.
In Grade 4 we will not yet work with decimals, but it is important to know now that a comma (,) indicates decimal numbers.
When we multiply, the comma (,) moves the number of zeros that the number has to the right. When we divide, the comma (,) moves the number of zeros to the left.
If there is no comma (,) in the number, we picture an imaginary comma at the end of the number.
Study the examples again. Can you see how the number of zeros in the number has an influence on the place values (and how the comma moves between the place values)? It is an easy way to quickly multiply and divide by 10, 100 and 1000.
