Page 137 - Start Up Mathematics_5

Conversion from °C to °F

9
The formula to convert °C to °F is × °C + 32 = °F .
5
Example 11: Convert 26°C to °F.

Solution: 9 × 26°C + 32 = 234 + 32 (multiply by 9)
5 5
= 46.8 + 32 (divide by 5)
= 78.8°F (add 32)
So, 26°C = 78.8°F.

Conversion from °F to °C
5
The formula to convert °F to °C is (°F – 32) = °C .
9

Example 12: Convert 113°F to °C.
5
Solution: 5 (113° – 32) = (81) (subtract 32)
9 9
= 405 (multiply by 5)
9
= 45°C (divide by 9)
So, 113°F = 45°C.

EXERCISE 9.3

1. Convert from °C to °F.
(a) 15°C (b) 28°C (c) 31°C (d) 42°C (e) 54°C
(f) 63°C (g) 74°C (h) 85°C (i) 92°C (j) 30°C

2. Convert from °F to °C.
(a) 36°F (b) 48°F (c) 97°F (d) 105°F (e) 112°F

(f) 124°F (g) 155°F (h) 193°F (i) 209°F (j) 212°F

Money

We already know how to add, subtract, multiply and divide money. Let’s revise these concepts
using large numbers.

Example 13: Add ` 362.35 and ` 1,496.74.
Solution: ` p Try This!

1 1 Add ` 756.23, ` 374.96
3 6 2 . 3 5 and ` 2,045.15
+ 1 4 9 6 . 7 4
1 8 5 9 . 0 9

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