Fifty Toes                                                      Number, Level 1

Problem
Sam likes counting toes. How many people does he needbefore he can count 50 different toes?

What is this problem about?
This problem involves counting by 10s.  As our number system is based on groups of ten, counting in 10's is an important skill.

Achievement Objectives
Number (Level 1)
- model and explain addition calculations with a sum of up to 20
- make sensible estimates and check the reasonableness of answers

Mathematical Processes
- devise and use problem solving strategies (act it out, draw a picture)
- use equipment appropriately

Resources required
Blackline master of the problem

Specific learning outcomes
The children will be able to:
- count in 10's to 50

1. Get the children to guess the subject of the problem by giving clues:  you have 10 of these, you often can't see them...
2. Read the problem to the class.
3. Discuss ways that the problem could be solved. Remember to allow time for the children to think before getting ideas from the class. If the children have had experience in solving problems you may choose not to share ideas at this point.
4. Reinforce the counting in 10's as you circulate while the children work on the problem. Ask the children to show you how they are keeping track of their counting in 10's.
5. Share solutions.

Other contexts for the problem
How many 10c coins to get 50 cents?

Solution
5 (10..20..30..40..50)