Multi-step addition & subtraction problems
Theory
A multi-step problem needs more than one calculation. Break it into steps, do them in order, and carry the result of each step into the next — then check you have answered the actual question.
A multi-step problem needs more than one calculation to answer.
Break it into steps, decide the operation for each, and work them out in order.
Carry the answer from each step into the next, and check at the end that you have answered the actual question.
Set the steps out in order and carry each answer forward:
| Step | Calculation | Result |
|---|---|---|
| 1 | \(3450 + 2780\) | \(6230\) |
| 2 | \(6230 - 1960\) | \(4270\) |
How to solve a multi-step problem
- Break the problem into steps and choose the operation for each.
- Work them out in order, carrying each answer into the next step.
- Check the final answer against an estimate and the question asked.
| \(3450 + 2780\) | \(=\) | \(6230\) |
| \(6230 - 1960\) | \(=\) | \(4270\) |
There are \(4270\) books.
| \(15\,000 - 6250\) | \(=\) | \(8750\) |
| \(8750 - 3800\) | \(=\) | \(4950\) |
There are \(4950\) L left.
| \(24.50 + 18.75\) | \(=\) | \(43.25\) |
| \(50.00 - 43.25\) | \(=\) | \(6.75\) |
Her change is $6.75.
| \(1250 + 980 + 1475\) | \(=\) | \(3705\) |
| \(5000 - 3705\) | \(=\) | \(1295\) |
They are $1295 short.
Common pitfalls
Frequently asked questions
How do you solve a multi-step problem?
Break it into steps, choose the operation for each, and do them in order, using each answer as the start of the next step.
How do you keep track of the steps?
Write each step out and carry its result forward. \(3450+2780=6230\), then \(6230-1960=4270\).
Why estimate a multi-step problem?
An estimate checks the final answer is sensible, which catches mistakes made along the way.
What is a running total?
It is the answer so far, carried from one step to the next until the problem is finished.