How to play Area & Perimeter Explorer

  1. Choose a colour, then tap a square or drag across several to colour them.
  2. Every shape is measured as you make it: the area is the squares it covers, the perimeter is the edges round its outside.
  3. Squares of the same colour that touch make one shape; different colours make separate shapes.
  4. Press Challenge to get a target area and perimeter, and colour a shape that matches both.

For parents and teachers

Six squares in a row have a perimeter of 14, but the same six squares as a two-by-three block have a perimeter of 10. A child who colours both sees that area and perimeter are different measurements, without needing a formula. Try asking for the longest and the shortest perimeter that can be made with the same number of squares.