Area: counting squares
Area is how much flat space a shape covers. On centimetre-squared paper, each square is 1 square centimetre (1 cm²).
- Count the whole squares.
- Two half squares make one whole square.
6 whole squares + 2 half squares (= 1 whole) → area = 7 cm²
Watch out! Don’t count a half square as a whole one. Count the halves, then halve that number.
Estimating the area of a curved shape
When a shape has curvy edges, you estimate:
- Count the squares that are completely covered.
- Count the squares that are more than half covered, as whole squares.
- Ignore squares that are less than half covered.
- Add steps 1 and 2 together.
Volume: counting cubes
Volume is how much space a solid shape takes up. Each centimetre cube is 1 cubic centimetre (1 cm³).
Count layer by layer: the bottom layer has 3 × 2 = 6 cubes, and there are 2 layers → 6 + 6 = 12 cm³.
Watch out! Some cubes are hidden behind or underneath others. Every cube you can see on top is sitting on a stack, so count the whole stack.
| Measures | Unit | |
|---|---|---|
| Area | flat space (squares) | cm² (“square centimetres”) |
| Volume | solid space (cubes) | cm³ (“cubic centimetres”) |
Top tip: for a box shape (a cuboid), volume = length × width × height. For a rectangle, area = length × width.
Each square is 1 cm². What is the area of the shape?
Estimate the area of the shape.
Count the squares that are more than half covered. Each square is 1 cm².
Shade squares to make a shape with an area of 6 cm².
Shaded: 0 cm²