 Estimate the lengths of objects (mm, cm, m, km)

Lesson

Before we start

We've looked at units of length, let's just quickly refresh our memory of the units, to see which are bigger or smaller.

How to tackle problems

Now we're ready to look for clues to estimate lengths. This video shows you how you can tackle problems, with some strategies to use.

Remember!

Often, we can compare to things we know, to compare lengths. We can also think about what makes sense, or is possible. Making sure our lengths are using the same unit of measurement is also important.

Worked examples

Question 1

Choose the best estimate for the distance from one side of a city to the other.

1. $1$1 kilometre

A

$500$500 kilometres

B

$1500$1500 kilometres

C

$30$30 kilometres

D

$1$1 kilometre

A

$500$500 kilometres

B

$1500$1500 kilometres

C

$30$30 kilometres

D

Question 2

Choose the best estimate for the length of a fingernail.

1. $100$100 millimetres

A

$60$60 millimetres

B

$10$10 millimetres

C

$1$1 millimetre

D

$100$100 millimetres

A

$60$60 millimetres

B

$10$10 millimetres

C

$1$1 millimetre

D

Question 3

Choose the best estimate for the length of a ladybug.

1. $30$30 centimetres.

A

$4$4 millimetres.

B

$40$40 millimetres.

C

$4$4 centimetres.

D

$30$30 centimetres.

A

$4$4 millimetres.

B

$40$40 millimetres.

C

$4$4 centimetres.

D