Measuring mass in kilograms

What are kilograms?

When you measure the mass of an object that is more than 1,000 grams, you should describe it in kilograms.

Kilograms can be shortened to 'kg'.

1 kilogram = 1,000 grams

or

1kg = 1,000g

Quiz: Measuring in kilograms

Test out your knowledge of measuring mass in kilograms with this quiz, then read on to complete the page.

Grams and kilograms

Here is a paper clip. It has a mass of 1 gram, which can be written as 1g.

What would be the mass of 1,000 paper clips?

They would have a mass of 1,000g.

When the mass of an object is heavier than 999g, we use another type of measurement.

Working with numbers in the thousands would become difficult, so we use kilograms instead.

There are 1,000 grams in a kilogram. You use the letters 'kg' after the number to represent kilograms.

1,000 paper clips would have a mass of 1kg in total.

Food that you buy in the shop is usually measured in grams and kilograms.

Here are some examples of objects that could have a mass of 1 kilogram.

Here are some objects that often have a mass of more than 1 kilogram.

Measuring the mass of objects

You can use balance scales to measure the mass of objects in kilograms.

Masses for weighing can come in 1kg, 2kg, 5kg, 10kg, 20kg and more.

You can also use a set of scales showing the mass on a dial with a pointer.

Or digital scales, such as these, which show the mass as a number.

Reading scales

You can use your knowledge of number lines to help you read scales.

Because weighing scales are often small, you don’t always see all of the numbers marked on them.

This number line shows where some numbers would be on a number line to 100 in tens.

To read the dial on scales, it’s the same thing but the number line goes round in a circle.

Here is the number 25 on a scale.

Example 1

Use balance scales to measure the mass of the following objects.