Measuring mass in g and kg

Home learning focus

Learn how to measure mass in grams and kilograms.

This lesson includes:

  • one video
  • a learning summary
  • three activities


Let's begin today's lesson with a visit to the vets to find out the difference between grams and kilogram.

How much do you think a mouse weighs compared to a snake? Watch this video to find out!

Measuring mass comes in handy all the time. Whenever you bake or cook, you have to use scales to weigh the ingredients. If you didn’t use the correct amount of flour in a cake, it would not taste nice!

When measuring mass, you use grams and kilograms.

1000 g = 1 kg

When you’re reading scales, you have to look really carefully at the intervals (divisions) between the numbers. This is so you can identify which numbers they represent.

The scales tell you whether you are reading grams or kilograms.

Example 1:

Take a look at the scales below.

When reading scales, the first thing you have to do is look at the intervals. What are the divisions going up in?

The larger intervals go up in hundreds. You can also see there is a smaller interval in between each hundred. This must be worth 50 g since it is the halfway point between hundreds.

The arrow on the dial is pointing at the smaller division between 700 g and 800 g, so the mass of the fruit must be 750 g

Example 2:

This time, the scales are in kilograms.

The arrow is between 2 kg and 3 kg, but what do the intervals represent?

The kilograms are split up into 10 divisions, so each one must represent 100 g, since 10 lots of 100 g is 1 kg.

The arrow is on the third division after 2 kg, so the weight of the potatoes is 2kg 300g

What would 2 kg 300 g be in just grams?

2 kg is the same as 2000 g. So:

2000 g + 300 g = 2300 g

Example 3:

How would you draw an arrow to represent the mass of 7 kg and 800 g?

First thing to do is work out what the smaller divisions represent in-between the whole kilograms.

The kilograms are split up into 10 divisions, so each one must represent 100g.

Now, you have to find the 8th division after 7kg and draw an arrow to represent 7kg 800g.

Like this:


Activity 1

Practise measuring mass with this worksheet. You can print out the activities or make a note of your answers on a sheet of paper.

Measuring mass

Check here for the answer sheet.

Activity 2

Test yourself with this quiz on grams and kilograms.

Activity 3

Karate cats

Play the measurements level of Karate Cats Maths - can you collect a cool new costume for your cats?

Game - Karate Cats Maths

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