The long number questions at the end of a paper: best buys, paint and turf, exchange rates, interest, reverse percentages and bounds, worked one clear step at a time.
What you will learn
- Plan a multi-step number problem before calculating
- Show every step so method marks can be given
- Round at the right moment, and round up for whole items
- Make a decision and back it with a figure
Plan before you calculate
A 5-mark problem is a chain of small steps.
Before you start, write down what you are aiming for and what you need to get there.
- aim: the cost of the paint
- need: the area to paint, the number of coats, how much a tin covers, the price of a tin
- area: 4.5 × 2.4 = 10.8, minus the door 0.9 × 2 = 1.8, gives 9 m²
- paint: 9 × 2 coats = 18 m², and 18 ÷ 5 = 3.6 tins
- tins come whole: round up to 4, so 4 × £12.50 = £50
Each line is a method mark on a paper. If the last line goes wrong, the earlier ones still score.
The rest of this lesson and its 12 practice questions are locked.
In this lesson
- Plan before you calculate
- Where the marks go
- Bounds
- Methods that come up
- Try it: An easy one first
12 practice questions, marked as you go; about 30 minutes in all.
Key terms
Down, Prices in two currencies, Compound against simple interest, Reverse percentages and profit, Standard form
In this unit: Exam problems
The long problems that end a paper, worth 4 to 6 marks: number, algebra, ratio, geometry and statistics, Foundation and Higher, with and without a calculator, marked step by step.