🔢 Numbers & shapes · Ages 6–7 · about 3 weeks

Length and Mass

Goal: Measure length in centimetres with a ruler, and compare mass with a balance.

For parents: The most common ruler mistake is starting at 1 instead of 0. Check where your child lines up the object.

Do together

  1. Ruler hunt

    You need: A 30 cm ruler, small objects (pencil, spoon, eraser)

    Line each object up with the 0 and read the number at the other end. Record it: pencil — 14 cm.

  2. Coat-hanger balance

    You need: A coat hanger, two bags, string

    Compare fruits: which is heavier, an apple or an orange? How many cubes balance a potato?

  3. Estimate first

    You need: The ruler and objects

    Guess how long something is before measuring. Who got closest? Estimating gets better with practice.

Talk about it

  • Where do we start measuring on the ruler?
  • Which side of the balance goes down? Why?
  • Was your guess too big or too small?

Words to use

  • centimetre
  • ruler
  • length
  • mass
  • heavier
  • lighter
  • balance

Play

  • Size Safari
    Measuring
  • Number Train
    Number order
  • Counting Stars
    Counting
Play these games free

Every game is free for every family until 20 November 2026.

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