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- Measures: scales, time and money
Measures: scales, time and money
Lots of marks are lost on everyday measures: misreading a scale, treating hours like decimals, or rounding money badly. These skills appear across many GCSE questions.
Reading scales
First work out what one small division is worth.
If there are 4 equal gaps between 200 g and 300 g, each gap is 100 ÷ 4 = 25 g.
Then count on from the nearest labelled mark.
If there are 4 equal gaps between 200 g and 300 g, each gap is 100 ÷ 4 = 25 g.
Then count on from the nearest labelled mark.
Time
There are 60 minutes in an hour, not 100.
1.5 hours = 1 hour 30 minutes. 0.2 hours = 0.2 × 60 = 12 minutes.
24-hour clock: add 12 to afternoon hours. 4:35 pm = 16:35.
For durations, count up to the next whole hour, then on.
1.5 hours = 1 hour 30 minutes. 0.2 hours = 0.2 × 60 = 12 minutes.
24-hour clock: add 12 to afternoon hours. 4:35 pm = 16:35.
For durations, count up to the next whole hour, then on.
Money and best buys
Money has 2 decimal places: £6.5 is written £6.50.
Best buy: find the cost of one item (or one gram) for each offer, then compare.
6 for £2.70 is 45p each; 10 for £4.20 is 42p each, so 10 for £4.20 is better value.
Best buy: find the cost of one item (or one gram) for each offer, then compare.
6 for £2.70 is 45p each; 10 for £4.20 is 42p each, so 10 for £4.20 is better value.
A film starts at 18:45 and lasts 1 hour 50 minutes. When does it finish?
- 18:45 + 1 hour = 19:45
- 19:45 + 15 minutes = 20:00
- 35 minutes left: 20:35
Answer: 20:35
Find the value of one division before reading a scale. An hour has 60 minutes, so convert decimal hours by multiplying by 60. Compare offers by working out the price of one unit.
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