Problem
Emma had a $5 note. She exchanged it with her brother Sam for three coins. What were the three coins?

What is this problem about?
This problem shows a knowledge of both coins and what three whole numbers add to 5. It can also be solved using play money.

Achievement Objectives
Measurement (Level 1)
- compare the value of coins and notes.

Mathematical Processes
- devise and use problem solving strategies to explore situations mathematically;
- use equipment appropriately.

Resources
- coins and $5 note
- Blackline master of the problem

Specific learning outcomes
The children will be able to:
- identify the value of coins and notes to $5.

1. Play "guess the coin" giving clues on its size, its picture, colour etc.
2. Pose the problem to the class.
3. As the children work, either individually or with a partner, ask them questions that focus their thinking on the coins.
   Which coin has the largest value?
   What could you buy with this coin?
   Can you tell me what is on the other side of this coin?
4. Share solutions.

Extension to the problem
Emma exchanged the $5 note for 5 coins. What could they be?

Solution
The three coins are two $2 coins and a $1 coin.