7. Measurement

Lesson

Estimating the length of objects can help us in this lesson. Let's try a problem to review.

Choose the best estimate for the length of a fingernail.

A

100 millimetres

B

60 millimetres

C

10 millimetres

D

1 millimetre

Worked Solution

Idea summary

To estimate the length of an object, we can compare it to an object where we have an idea already of its estimated length.

Let's look at the units for volume of \text{mm}^3, \text{cm}^3, and \text{m}^3.

Which of these is the bigger volume?

A

1 \text{ mm}^3

B

1 \text{ cm}^3

Worked Solution

Idea summary

Units of volume from smallest to biggest: \text{mm}^3, \text{cm}^3, and \text{m}^3.

How do you know which unit to use?

What is the most appropriate unit for measuring the volume of a box?

A

\text{ cm}^3

B

\text{ mm}^3

Worked Solution

Idea summary

A cubic millimetre \left(\text{mm}^3\right) is about as big as a grain of sand.

A cubic centimetre \left(\text{cm}^3\right) is about as big as the end of your thumb.

A cubic metre \left(\text{m}^3\right) is about as big as a washing machine.

selects and uses the appropriate unit to estimate, measure and calculate volumes and capacities, and converts between units of capacity