The size of something does not determine how much mass (or matter) an object has.
Taller containers do not always hold a greater volume of liquid.
If you know the mass and volume of some objects, it is easier to estimate others by comparing them.

Common misconception

Larger objects have a greater mass. Taller containers have a greater capacity and/or volume.

The size of something does not determine how much mass an object has; taller containers may be narrower and so may not hold as much liquid.

Keywords

Estimate - An estimate is a given value, number or quantity that is near to the true amount; it is a number close enough to the right answer.
Mass - Mass is a measure of how much matter something contains. It is measured by how much something weighs. Mass can be measured in g or kg.
Volume - Volume is the specific amount of liquid in a container. Volume can be measured in millilitres or litres.

As before, children should experience this lesson practically. Find some same-size balls with different masses; larger objects that have a smaller mass than smaller objects and taller containers that have a smaller volume than shorter, wider ones.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Worksheet

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Starter quiz

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6 Questions

Q1.

Which of these would you use grams to measure?

The length of a bus.

The volume of liquid in a cup.

Correct answer: The mass of an egg.

Q2.

Look at these objects. Which has the greater mass?

The feather has the greater mass.

Correct answer: The car has the greater mass.

The mass of the feather and car are the same.

Q3.

A glass holds 250 ml of water. Compare this volume to a volume of one litre. Which statement is true?

Correct answer: 250 ml is less than one litre.

250 ml is more than one litre.

250 ml and 1 L are the same volume.

Q4.

What is the mass of this teddy bear?

Correct Answer: 150 g, 150, 150g

Q5.

What volume of water is in this jug?

40 ml

Correct answer: 80 ml

90 ml

Q6.

Starting with the smallest, put these containers in order of their capacity.

1 - C

2 - A

3 - B

Exit quiz

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6 Questions

Q1.

Look at these two bags. They are the same size. Will they have the same mass?

Yes

Correct answer: The could have, but we cannot be certain.

Q2.

Look at these bags. Which has the greater mass?

The green bag has the greater mass.

The orange bag has the greater mass.

Correct answer: I cannot be certain.

Q3.

Look at these containers. Which has the greatest capacity?

Correct answer: I cannot be certain.

Q4.

Andeep holds a pebble and compares its mass to the mass of a 50 g egg that he is holding. The pebble feels lighter than the egg. Which statement is true?

The pebble's mass must be greater than 50 g.

Correct answer: The pebble's mass must be smaller than 50 g.

The pebble must have a mass of 50 g.

Q5.

The mass of a toy car is smaller than the mass of a 50 g egg but greater than that of a 10 g pound coin. What could its mass be?

5 g

Correct answer: 30 g

Correct answer: 45 g

75 g

Q6.

Using these clues, starting with the object with the smallest mass, put these objects in order.

1 - Leaf

2 - Pebble

3 - Twig