We often compare objects and distances by length and height. Children can first do this without using units, then using informal units (like paces). Then they learn about metres, centimetres and kilometres. Also:

• When you are measuring with sewing or building material, ask the children to estimate where a particular mark would be
• Put up a height measure for children marked in centimetres on which the children can record their height at progressive intervals, such as once every two months. The children take an interest in the way that they grow, and it also provides a language for describing how their height is changing.
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