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What is mass?

What is mass?
We explain what mass means, how mass is usually measured and how children are taught to convert from one unit of mass to another.
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What is mass?

Sometimes people talk about an object having a 'mass' of 2 kilograms. This is another way to refer to the weight of an object.

SATs questions have been known to trip children up by asking them a question about the 'mass' of an object rather than the 'weight', so it's a good maths vocabulary word to know!

How is mass measured?

Mass or weight is usually measured in grams and kilograms.

Children need to learn that there are 1000g in a kilogram. As they move up primary school, they need to be able to convert from one unit to another, so they would need to know that 1.2 kg is 1200g, or that 900g is 0.9kg.

Sometimes, children will learn about 'the mass' of an object in science.