Multi-step problems: choosing operations
Solve problems involving addition, subtraction, multiplication, and division, deciding which operations and methods to use and why; solve multi-step problems in contexts
What a learner can do afterwards
- Solve a three-step word problem involving a mix of all four operations
- Explain why particular operations were chosen for each step of a multi-step problem
- Identify and correct an error in a multi-step solution that used the wrong operation
The lesson
Some word problems need more than one step to solve. Break the problem into smaller parts, and solve them in the order the story happens. Before you calculate, decide what each step is really asking you to do, then use that step's answer to help with the next one.
Zara buys 3 notebooks at £2 each and 2 pens at £1 each, and pays with a £10 note. Step 1: 3 × 2 = £6 for the notebooks. Step 2: 2 × 1 = £2 for the pens. Step 3: 6 + 2 = £8 total cost. Step 4: 10 − 8 = £2 change.
Look for clue words to help you pick each operation. 'In total' or 'altogether' can mean add. 'Left' or 'change' can mean subtract. 'Each' or 'times' can mean multiply. 'Share equally' or 'split' can mean divide. Always check that the operation makes sense for what is happening in the story.
Break the problem into steps, choose the right operation for each one, and carry each answer into the next step.
Watch it
Where it sits
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.