Question 4 on the Maths 2010 Paper A introduces the important notion that you don’t necessarily have to get a question correct to gain marks. Part 4b points out that showing the working out could gain a mark and it is very important that children realise this. Many children are very reluctant to show their working out, preferring to just jot down and answer.
Both parts of question 4 require two separate operations to reach the answer.
Part (a) can be done in several ways. The most obvious is to identify the cost of the tuna salad (£1.60) and the apple pie (50p) and add them together. £1.60 + 50p = £2.10. This is quite tricky as it involves adding pounds and pence. Then subtract £2.10 from £2.50, leaving £0.40 or 40p.
Another way of doing part (a) is to do two separate subtractions. Take 50p from £2.50 leaves £2.00. Take £1.60 away from £2.00 leaves £0.40 or 40p. I think this is probably an easier method for many children.
The most appropriate method for part (b) is to add the cost of the cheese salad (£1.20) to the yogurt (35p) which makes £1.55. Then subtract 90p from £1.55 leaving £0.65 or 65p.
Some children may well subtract 90p from £1.20, making £0.30 and then adding the cost of the yogurt (£0.35), making £0.65 in total.
Both questions involve money written in a mixture of pounds and pence which makes this harder than it might first appear.