The Pencil Case - Estimation

I like to start my students on estimation using non-standard units, then progress to non-standard units of a standard length (e.g. strings of 1M), then to formal units.

Making a picto graph is a great way of having students record their measuring in a concrete way. For example, my students measured themselves using rulers - not in standard units, but how many rulers they are tall - and we made a picto-graph using pictures of rulers. This way the students were able to identify the tallest person and match them to the tallest column of rulers. Remembering that my students are at various levels of ability, this gave me a lot of scope. For some of the students, the goal was to identify longest and shortest. For another it was to tell how many rulers taller I was than he.

We do a lot of informal estimation, e.g.:

I'm sure you get the idea by now.

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