For the next three days students will spend time experimenting and finding personal and external benchmarks for carryout practical measuring tasks. This will be followed by children using standard measuring devices to check their estimated lengths of given objects.
Ask the question "Having a metre benchmark is handy when you need to measure what kinds of things?" The aim of this next lesson is to equip children with other key benchmarks like "a metre" and "1 cm" so that they can estimate the lengths of objects that are a lot smaller than 1 metre in length.
Ask children the following question "What other personal benchmarks do you think would be useful to have?" Brainstorm possibilities ensuring that benchmarks are just that - a few key measurements to aid in estimating lengths of various objects. Discuss the importance of not having too many.
Now point to items around the room and say, "Don't estimate the length tell your partner what benchmark you would use to estimate the length of that particular object." For example point to the door, and ask the children to decide which of their benchmarks they will use to help them estimate its height. Ask them to justify their decision.
"What personal benchmark would you use to estimate the length of
Send the children off in pairs to create benchmarks for half a metre, one centimetre and maybe one other of their choice.
Provide children with a list of the various objects from around the room to firstly acknowledge which bench mark they think would be most useful to use in estimating the length of given objects and then using the benchmark to make an actual estimate. Obviously the items to be recorded will vary according to the resources and features within your own school. This activity could be turned into a measurement trail, where children rotate or move around the trail of items to be measured.
Adaptation for NESB students: Check on the language being used, encourage accuracy with mathematical language and recycling of the new vocabulary.
Published on: 09 Jan 2018
