Multi-step number problems from everyday life: 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 you, or anyone checking, can follow it
- 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 real problem, like painting a room, 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
Writing each step on its own line lets you, and anyone checking, follow the chain. If the answer looks wrong, you can find the line where it slipped and fix just that one.
The rest of this lesson and its 12 practice questions are locked.
In this lesson
- Plan before you calculate
- Show your working
- 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: Putting it together
Multi-step problems in real contexts, where one result feeds the next: number, algebra, ratio, geometry and statistics, Foundation and Higher, with and without a calculator, checked step by step.