The idea, step by step
Each item adds to the total
When you buy two things, include the price of both. A pencil costing two dollars and a bookmark costing one dollar cost three dollars together.
Touch or list each item as you add its price. This helps you include every item once.
| Item | Price |
|---|---|
| Pencil | 2 dollars |
| Bookmark | 1 dollar |
| Notebook | 5 dollars |
The same price can appear again
Two pencils each cost two dollars. Add two for the first pencil and two for the second. Together they cost four dollars.
You can start counting from the larger price. For a five-dollar notebook and a one-dollar bookmark, start at five and count one more.
A common trap
Adding only one price when buying two of the same item.
Instead: Count the price once for every item. Two pencils need two pencil prices.
See the thinking
Two different items
A pencil costs two dollars and a bookmark costs one dollar. What is the total?
- The pencil adds two dollars.
- The bookmark adds one dollar.
- Two and one make three.
Three items
Buy two two-dollar pencils and one one-dollar bookmark. What is the total?
- Two pencils cost two and two, making four dollars.
- The bookmark adds one dollar.
- Four and one make five.
Check your understanding
A card costs three dollars and a sticker costs one dollar. What do they cost together?
Show answer
4 dollars.
Start at three and count one more.
Your turn
6 questions · Work at your own pace.
Read the questions online
- A ruler costs one dollar and a pencil costs two dollars. Find the total.
- Two cards each cost three dollars. Find their total cost.
- A notebook costs five dollars and a badge costs two dollars. Find the total.
- Three bookmarks each cost one dollar. Find the total.
- A ball costs four dollars. A book costs five dollars. You have ten dollars. Can you buy both?
- Rae adds two dollars and one dollar and says the total is two dollars. Explain the mistake.
Read the worked solutions
- A ruler costs one dollar and a pencil costs two dollars. Find the total.
One and two make three.
3 dollars. - Two cards each cost three dollars. Find their total cost.
Three and three make six.
6 dollars. - A notebook costs five dollars and a badge costs two dollars. Find the total.
Count on from five: six, seven.
7 dollars. - Three bookmarks each cost one dollar. Find the total.
One plus one plus one makes three.
3 dollars. - A ball costs four dollars. A book costs five dollars. You have ten dollars. Can you buy both?
Four and five make nine. Nine is less than ten.
Yes. Both cost 9 dollars. - Rae adds two dollars and one dollar and says the total is two dollars. Explain the mistake.
The one-dollar item must be included: two and one make three.
The total should be 3 dollars.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Year 1 money modelling, needs and wants, simple class enterprise and consequences of financial choices. Activities use supplied pretend prices and whole-dollar amounts.
Official curriculum source ↗