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Ireland: choose your country
Third Class maths · J.2 · Length Relationships

Convert centimetres and millimetres

1 cm = 10 mm. Smaller units make a bigger count; bigger units make a smaller count.

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  1. 30 mm = ___ cm

    Answer: 3 cm

  2. 1 cm = ___ mm

    Answer: 10 mm

  3. 2 cm = ___ mm

    Answer: 20 mm

Tip: 1 cm = 10 mm. Smaller units make a bigger count; bigger units make a smaller count.

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Curriculum

Common Core: 2.MD.A.2

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On paper: this skill is in the printable pack Grade 3 Common Core Math: Geometry and Measurement, with an answer key.

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