Money word problems
Theory
Money word problems are a Year 4 skill: read a story about dollars and cents, choose the right operation, and solve it. This Year 4 maths page shows how to work out a total, find change, handle equal groups, and answer “how much more?” — using bar models to see the parts and the whole. Curriculum: VC2M4N09 / AC9M4N08.
A money word problem is a short story about dollars and cents. It does not tell you which operation to use, so your first job is to work out whether to add, subtract or multiply.
The words are your clue. Total, altogether and in all mean add. Change, how much is left and how much more mean subtract. Each, every and groups of point to equal groups, so you multiply.
Some problems need two steps, such as finding a total and then the change. Work through the steps in order, keep the dollar sign and any cents in every line, and check the answer makes sense.
Money word problems use a few simple rules. Learn the key words and these number sentences.
| Key words | Operation |
|---|---|
| total, altogether, in all, earn, win, sell | add |
| spend, change, left, how much more, difference | subtract |
| each, every, groups of | multiply |
How to solve any money word problem
- Read and picture it. What is happening in the story, and what is the question really asking — a total, the change, or how much more?
- Choose the operation. Use the key words to decide: add for a total, subtract for change or how much is left, multiply for equal groups. Draw a bar model if it helps.
- Work it out, step by step. Do each step in order, keep the dollar sign and cents, then check the answer is sensible for the story.
| \(\$8.50 + \$6.50\) | \(=\) | \(\$15.00\) |
| \(\$20.00 - \$15.00\) | \(=\) | \(\$5.00\) |
Find the total first, then subtract it from \(\$20\). The change is \(\$5.00\).
| \(4 \times \$9\) | \(=\) | \(\$36\) |
| \(\$36 + \$5\) | \(=\) | \(\$41\) |
Equal groups multiply, then add the juice. They spend \(\$41\).
| \(7 \times \$4\) | \(=\) | \(\$28\) |
| \(8 \times \$4\) | \(=\) | \(\$32\ (\text{too much})\) |
Seven packs cost \(\$28\), leaving \(\$2\). Zoe can buy \(7\) packs.
| \(\$45 - \$28\) | \(=\) | \(\$17\) |
The goal minus what he has gives the gap. Sam needs \(\$17\) more.
| \(\text{start}\) | \(=\) | \(\text{spent} + \text{left}\) |
| \(\$27 + \$16\) | \(=\) | \(\$43\) |
Ella started with \(\$43\). Check: \(\$43 - \$27 = \$16\).
| \(5 \times \$2\) | \(=\) | \(\$10\) |
| \(\$10 - \$8\) | \(=\) | \(\$2\) |
The pack is cheaper. You save \(\$2\).
Common pitfalls
Frequently asked questions
How do you solve a money word problem?
Read the story, decide what it is asking, then choose the operation. Add for a total, subtract for change or how much is left, and multiply for equal groups. Do two-step problems one step at a time, then check the answer makes sense.
How do I know whether to add or subtract in a word problem?
Look at the words. Total, altogether and in all mean add. Change, how much is left and how much more mean subtract. A bar model helps: if you know the parts you add to find the whole, and if you know the whole and one part you subtract to find the missing part.
How do you work out change?
Change is the money you get back. First add up what you spend, then subtract that total from the amount you paid. If you spend \(\$15\) and pay with a \(\$20\) note, the change is \(\$20 - \$15 = \$5\).
What is a two-step money problem?
A two-step problem needs two calculations. Buy \(4\) pizzas at \(\$9\) each, then add a \(\$5\) juice: first \(4 \times \$9 = \$36\), then \(\$36 + \$5 = \$41\). Do the steps in order and keep the dollar sign in every line.
How do you find how much more money you need?
Subtract the money you have from the amount you need. If a scooter costs \(\$45\) and you have saved \(\$28\), you need \(\$45 - \$28 = \$17\) more.
How do you add dollars and cents?
Line up the dollars with the dollars and the cents with the cents. Add the cents first, and if they make \(100\) cents or more, carry a dollar. For example, \(\$4.50 + \$3.50 = \$8.00\), not \(\$7.00\).
How do you work out how much money someone started with?
Add what they spent to what they have left. If Ella spent \(\$27\) and has \(\$16\) left, she started with \(\$27 + \$16 = \$43\).
How can I tell if I can afford two things?
Add the two prices and compare the total with your money. With \(\$30\), a \(\$18\) hat and a \(\$14\) scarf cost \(\$32\) together, which is too much, but you could buy either one on its own.
How do you compare prices at two shops?
Find the total cost of everything at the first shop, then at the second shop. Subtract the smaller total from the larger total to find how much cheaper one shop is.