Area by counting squares, step by step
The first area a child meets is not a formula — it is counting.
The question
squares
Area of an L-shape by counting
an L, not a rectangle
whole:4 × 7 =28
bite:1 × 3 =3
28 − 3 =25
first way:28 − 3 =25
strip:4 × 4 =16
upright:3 × 3 =9
16 + 9 =25 squares
- There is no single row that runs all the way across this one, so counting rows does not work as it stands. Cut it into pieces that ARE rectangles — and there is more than one way.
- First way: count the whole rectangle it would be — 4 × 7 = 28 — then take off the bite, 1 × 3 = 3. That leaves 25.
- Second way: two rectangles. The strip underneath is 4 × 4 = 16, the part standing on it is 3 × 3 = 9, and 16 + 9 = 25. Two ways agreeing is how you know a count is right.
How it works.
- 01
There is no single row that runs all the way across this one, so counting rows does not work as it stands. Cut it into pieces that ARE rectangles — and there is more than one way.
- 02
First way: count the whole rectangle it would be — 4 × 7 = 28 — then take off the bite, 1 × 3 = 3. That leaves 25.
- 03
Second way: two rectangles. The strip underneath is 4 × 4 = 16, the part standing on it is 3 × 3 = 9, and 16 + 9 = 25. Two ways agreeing is how you know a count is right.