Units of area and volume
Units of area and volume
Area is measured in squares:
- cm² (square centimetre) – the area of a square whose side is 1 cm;
- m² (square metre) – the area of a square whose side is 1 m.
The square below is a square metre. Each small square in it is 10 cm by 10 cm, and its area is cm²:
A square metre holds 100 such squares, so it is cm². Another way to see it: a square metre’s side is 100 cm, so it holds 100 rows of 100 cm².
- A metre is 100 cm, but a square metre is cm².
- So 3 m² are cm².
Volume is measured in cubes:
- cm³ (cubic centimetre) – the volume of a cube whose side is 1 cm. One cm³ is also one ml (millilitre).
- A cube whose side is 10 cm is a dm³ (cubic decimetre). It holds cm³, and exactly one litre.
- m³ (cubic metre) – a cube whose side is 1 m. It holds dm³, that is 1000 litres.
Write each measure in the unit beside it.
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
A shop got 180 kg of sweets, in bags of 300 g.
How many bags did the shop get?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
Which juice is the cheapest?
- a 2-litre bottle for 5 ₪;
- a -litre bottle for 3.50 ₪;
- a 300 cm³ can for 2 ₪.
Explain how you decided.
A room’s floor was laid with 180 tiles of 20 cm by 20 cm.
How many tiles would it take if each tile were 0.3 m by 0.3 m?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power