Using measures

How we measure is really important in maths and in science. In this post there are problems to work though involving measure of time, length and weight in particular. There is also a section on decimals which is important in working with different metric units. At the end there is a clip about the development of metric units around the world and a famous puzzle for you to try out.


Can you work out what times each of the four clocks show?

Here are four different problems to solve using different measures, but are all about reading. You may use a calculator for these. The key skill is to select the right pieces of information and calculation to solve the problem.

How much do you read? Could you create your own problems to solve based around books and reading? Send these in to Student Showcase


Practise converting between the most commonly used metric measures of length by copying and completing the table below.

Write some notes or a diagram to show someone else how to convert between each of these units of measure.

In the next activity, Less marks are best, work out how you can use these marks to measure 1cm, 2cm, 3cm, and so on, up to 10cm.

Here’s how you might start:

Once you’ve completed this, up to 10 cm, then consider the following question. Can you find a way of marking the strip so that all the measurements can be made with fewer marks? How many?

How few marks would be needed to measure up to 10cm in half centimetres?

The following problems involve imperial as well as metric units of lengths. You may use a calculator for these. You will need to use proportional reasoning here.

Do you know anyone who enjoys knitting? Can you write some problems of your own based on that person? Send them in to Student Showcase


Solve these problems based on weighing scales.

Working with decimals

In this activity, you need to find any number that is between the numbers above and below. There are lots of possible answers.

Now try to make up your own difficult ones to challenge someone else.

Further ideas

Watch this clip to better understand when and how and why metric units were developed around the world.

This interactive task is based on a well known riddle (it appears in the film Die Hard 3). In this version, there is a 5 litre and a 7 litre jug and the aim is to measure out exactly 4 litres.

Once you’ve solved this first one you can try other puzzles with different sizes – scroll down the page to the section where you can click to change it:

ANSWERS – click below


Red clock: 10.45
Blue clock: 7.15
Yellow clock: 5.35
Green clock: 7.49