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Area

A square metre is bigger than it sounds

Matting, 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.
Step 1 of 4
  1. A square, 100 cm along each side.
  2. One row: 100 cm², a strip.
  3. 100 such rows.
  4. 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.

Three steps up the unit ladder
FromOne sideOne square of the bigger unit is
cm to mm10100 square mm
m to cm10010,000 square cm
km to m1,0001,000,000 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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This track

  1. 0 Start here
  2. 1 When a square is only half covered
  3. 2 A rectangle without counting
  4. 3 Cut a piece off and slide it across
  5. 4 Two of the same triangle, fitted together
  6. 5 The length that is the height
  7. 6 Two parallel sides, averaged
  8. 7 Awkward outlines, ordinary pieces
  9. 8 A square metre is bigger than it sounds
  10. 9 The big picture
  11. 10 Track quiz

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