1. Begin the session with a problem like "How far is it from one end of the mat to the other end of the mat?" (It could be a distance between 2 objects anywhere between 4-8 metres) Encourage children to record how they would estimate the length.
2. Ask children to share their estimates and solution strategies for example:
3. Share any of the strategies not shared by saying "I saw another child do it like this".
4. Summarise the discussion by saying that we have on board benchmarks that include body parts but there will be other benchmarks that we can use for example visualising the length of a 30 cm ruler, or knowing 1 stride back from an opponent in netball is 1 metre.
5. Organise children into groups of 3 or 4 to discuss other possible benchmarks that may be useful to add to your benchmark 'belt'. Allow students 2-3 minutes to discuss and record other possibilities. Record the responses under the heading 'other possible benchmarks'. For example children may come up with ideas like visualising a 30 centimetre ruler, knowing the length of a new pencil is 20cm.
6. Test out children's benchmarks by asking the various strategies and benchmarks they could use to work out how tall the chair is or how high the table is.
Published on: 09 Jan 2018
