Measuring and comparing mass

The mass of an object tells you how heavy something is.

You can measure mass in grams (g) and kilograms (kg).

Light items, like apples and bananas, are measured in grams.

Heavy objects, like a toy box or a person, are measured in kilograms

'Kilo' means 'times a thousand' or 'one thousand of'.

1 kilogram is equal to 1000 grams or 1kg = 1000g

Complete this interactive activity to understand how to compare mass. Then put your knowledge to the test.

When measuring mass, you use weighing scales. These can be digital or analogue.

On analogue scales, measurements may be marked in grams, kilograms, or both.

To measure the mass of an item, place it on the scale and read where the scale points.

You can use the 'greater than' (>) , 'equal to' (=) or 'less than' (<) signs to help you compare the mass of two objects.

On this set of scales you can see there is a small unlabelled mark halfway between each increment of 100g.

Example 2

Here are two scales.

On the first scale, the measurements are marked in grams. The scale goes up to 2000 grams.

On the second scale, the measurements are marked in kilograms. The scale goes up to 2 kilograms.

Example 3

Here is a scale where there are marks between each 100 grams.

The scale goes up to 1000 grams.