Understand the idea.
Money available sets a limit
A budget is a plan for the money you have available. Add all the prices before checking your limit. A total equal to your money is affordable, but leaves nothing. A total below it leaves money; a higher total needs more money.
| Item | Price in dollars |
|---|---|
| Small notebook | 3 |
| Pencil set | 4 |
| Paint box | 9 |
Save towards a goal
To plan saving, first find the gap between your savings and the price. Then count the amounts you can add each week until you fill that gap. Money spent along the way is no longer part of your savings.
See the method in action.
Check a budget
Leo has 8 dollars. He wants a 3-dollar notebook and a 4-dollar pencil set. Can he buy both? What will remain?
Worked solution
- 1
Add the costs of both wanted items.
Leo needs to pay for the notebook and the pencil set.
- 2
Compare the total with his money.
Seven dollars is less than the eight dollars available, so he can buy both.
- 3
Work out what remains.
After paying the total cost, Leo has one dollar left.
Yes. He will have 1 dollar left.
Plan saving
A craft kit costs 14 dollars. Isha has saved 8 dollars. She can save 2 dollars each week. How many more weeks will she need?
Worked solution
- 1
Find the amount still needed.
The eight dollars already saved covers part of the fourteen-dollar price.
- 2
Count the new savings each week.
Each week adds two dollars, and the missing six dollars is reached in week three.
- 3
Check that the full price is reached.
After three more weeks, her old and new savings together buy the craft kit.
3 more weeks.
Try it yourself.
Check your understanding
You have 9 dollars and want a 12-dollar book. How much more must you save?
Show answer & reasoning
3 dollars.
The book costs twelve dollars and nine dollars is already saved. The gap is , so three more dollars is needed.
Keep practising
6 worksheet questions
Read the questions online
- You have 6 dollars. Does a 5-dollar purchase fit your budget?
- You have 10 dollars. Can you buy items costing 6 dollars and 5 dollars together?
- A toy costs 15 dollars. You have 9 dollars. How much more must you save?
- You have saved 4 dollars. You save another 3 dollars. How much do you have?
- You need 8 more dollars and save 2 dollars each week. How many weeks are needed?
- You have 10 dollars for a 10-dollar book. If you buy a 2-dollar sticker first, can you still buy the book now? Explain.
Read the worked solutions
- You have 6 dollars. Does a 5-dollar purchase fit your budget?
.
Yes; 1 dollar remains. - You have 10 dollars. Can you buy items costing 6 dollars and 5 dollars together?
, which is greater than 10.
No. You need 1 dollar more. - A toy costs 15 dollars. You have 9 dollars. How much more must you save?
.
6 dollars. - You have saved 4 dollars. You save another 3 dollars. How much do you have?
.
7 dollars. - You need 8 more dollars and save 2 dollars each week. How many weeks are needed?
Count .
4 weeks. - You have 10 dollars for a 10-dollar book. If you buy a 2-dollar sticker first, can you still buy the book now? Explain.
Spending changes the money available for the goal.
No. You would have 8 dollars, so you would need 2 more.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Comparing prices; $1/$2 coins and notes; purchases; limited money and saving; needs/wants; consumer choices.
Official curriculum source ↗