Question

(a) Why can a pace or a footstep not be used as a standard unit of length? [1 mark]

(b) Arrange the following lengths in their increasing magnitude:
1 metre, 1 centimetre, 1 kilometre, 1 millimetre
[2 marks]

(c) The height of a person is 1.65 m. Express it in cm and mm.
[2 marks]

Answer 1

(a) A pace or a footstep cannot be used as a standard unit of length because the size of a pace or a footstep varies from person to person. This will lead to confusion while measuring lengths. (1 mark)

(b) Since, 10 mm = 1 cm, 100 cm = 1 m, and 1000 m = 1 km, the correct order of increasing magnitude is 1 millimetre, 1 centimetre, 1 metre, 1 kilometre.
(2 marks)

(c) Since, 1 m = 100 cm and 1 cm = 10 mm, therefore, 1.65 m = 1.65 × 100 cm = 165 cm
and 1.65 m = 1.65 × 1000 mm = 1650 mm.
(2 marks)