A square metre is bigger than it sounds
Show on a big screenMatting, a floor covering, costs ₹250 for each square metre (m²). A floor measures 20,000 square centimetres (cm²). What is the bill?
- A square, 100 cm along each side.
- One row: 100 cm², a strip.
- 100 such rows.
- 100 × 100 = 10,000 cm².
Use the 100 twice
The bill is ₹500. The floor is 2 m², and 2 × 250 = 500.
A metre is 100 centimetres. An area has a length and a width. So use the 100 twice. Then 100 × 100 = 10,000 cm² in one m².
| From | One side | One square of the bigger unit is |
|---|---|---|
| cm to mm | 10 | 100 square mm |
| m to cm | 100 | 10,000 square cm |
| km to m | 1,000 | 1,000,000 square m |
To change m² to cm², multiply by 10,000.
A verandah of 2.5 m² is 2.5 × 10,000 = 25,000 cm². The floor of 20,000 cm² is 20,000 ÷ 10,000 = 2 m².
An inch is 2.54 cm. A square inch is 1 in by 1 in. So 1 in² = 2.54 × 2.54 = 6.4516 cm².
Watch out!
A square metre is not 100 cm². 100 cm² is a patch 10 cm by 10 cm. The patch fits in a hand. A square metre does not.
Zoom in on one square metre. Then change m² to cm².
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