Comparing Lengths
Maths: Year 3 & 4 National Curriculum, topic 2.1.2
Comparing and Ordering Lengths
You can use your knowledge of units of length to work out which things are longer or taller or to put them in order.
Comparing pencils
- Some children measure their pencils using different units:
- Amy says hers is 90 mm.
- Sam says his is 12 cm.
- Who has the longest pencil?
Answer
- To compare the lengths of the pencils, we have to write them in the same units:
- 12cm = 120mm, as there are 10 mm in every cm.
- 90mm = 9cm
- So Sam’s pencil is longer than Amy’s.
Comparing plants
- The class measure some bean plants in the vegetable garden:
- Plant A is 150cm.
- Plant B is 1m 20cm.
- Plant C is 80cm.
- Order the plants' height from smallest to largest.
Answer
- Plant B has a height of 120 cm as there are 100 cm in every 1 m.
- Their height order from smallest to largest is:
- C (80cm), B (1m 20cm), A (150cm).
Test yourself on Comparing Lengths
Arrange the following measurements in order of length from the smallest (1) to the largest (5)
Arrange the following measurements in order of length from the smallest (1) to the largest (5)
Which is the longest length measurement?
Which is the shortest length measurement?