Page 51 - Mathematics Coursebook

4.3 Reading scales

4.3 Reading scales

When you read a scale you need to work out what each division on the scale represents.
On this scale there are four divisions between 0 and 100 g.

g 0 100 200

Each division represents 100 ÷ 4 = 25 g, so the arrow is pointing at 125 g.

Worked example 4.3

a Write down the value shown on this scale.
mm 30 40 50

40
b Estimate the reading on this scale.
30 kg 50

a 10 ÷ 5 = 2 There are 5 divisions between 30 and 40. Each division represents 2 mm.
Value = 38 mm 30 + 8 = 38 or 40 − 2 = 38
b 10 ÷ 2 = 5 kg There are 2 divisions between 40 and 50. Each division represents 5 kg.
Estimate = 42 kg The reading is almost halfway between 40 and 45, so 42 is a good estimate.

) Exercise 4.3 Don’t forget to include the

1 Write down the value shown on each of these scales. units with each answer.
a b c
48 cm 48
70 mm 70
cmcm 48 4949 49 mmmm 70 8080 80 9090 90 mm 3m 3 3 4 4 4 5 5 5
707070
484848
cmcmcm 494949 mmmmmm 808080 909090 mmm 3 33 4 44 5 55
d ml ml e 2020 20 f
ml
litres
200 200 202020 litreslitres
200
mlmlml
lit
litresresres
200200200 2 2 lit 2
10 10 10 kgkg kg 30 30 30 2 22
100
100 100 10 10 10 kgkgkg 30 30 1 1 1
30
100100100 1 11
0 0 0 0 0 0
0 00 0 00
2 Anil says that this scale shows a mass of 6.2 kg. 5
Is Anil correct? 6
Explain your answer. 4
kg

50 4 Length, mass and capacity 4 Length, mass and capacity