Comparing Masses
Maths: Year 3 & 4 National Curriculum, topic 2.2.2
Comparing and Ordering Masses
You can use your knowledge of units of mass to work out which things are heavier or lighter or to put them in order.
School bags
- Some children weigh their school bags.
- Amy says her bag is 1 kg 400 g.
- Sam says his bag is 980 g.
- Which school bag weighs the most?
Answer
- To compare the masses of the bags, we have to write them in the same units:
- 1 kg 400 g = 1,400 g
- 1,400 g is greater than 980 g, so the mass of Amy’s bag is greater than Sam’s.
- Amy’s school bag weighs more than Sam’s.
Flour
- The class have used some bags of flour for baking.
- They weigh them to find out how much is left in each one.
- Bag A has a mass of 1 kg 700 g.
- Bag B has a mass of 900 g.
- Bag C has a mass of 1,200 g.
Answer
- To order the masses, we need to write the mass of bag A in grams:
- 1 kg 700 g = 1,700 g
- The order of their masses from lightest to heaviest is B (9,00 g), C (1,200 g), A (1,700 g)
- Bag A has the most flour left.
Test yourself on Comparing Masses
Arrange the following measurements in order of mass from the lightest (1) to the heaviest (5)
Arrange the following measurements in order of mass from the lightest (1) to the heaviest (5)