This problem solving activity has a number (multiplication and division) focus.
Mother Bear is making her 5 bear cubs new coats.
The coats have 3 buttons each.
How many buttons does Mother Bear need?
- Count groups of three to 15.
- Use equipment to model and add sets of three.
- Devise and use problem solving strategies (act it out, draw a picture).
This problem involves repeated addition which is a prelude to multiplication. It can lead to skip counting in threes.
Other contexts for this problem could include triceratops and horns (3 horns per dinosaur), wheels on tricycles, or insect bites (3 bites per student).
- Copymaster of the problem (Māori)
- Copymaster of the problem (English)
- Teddy bears
- Buttons
The Problem
Mother Bear is making her 5 bear cubs new coats. The coats have 3 buttons each. How many buttons does Mother Bear need?
Teaching Sequence
- Read the problem to the class.
- Ask the students to identify the important information in the problem – highlight the identified words in the problem.
- Brainstorm ways to solve the problem.
- If they suggest drawing a picture encourage them to think less about the details in their picture (e.g. the colour of the teddies' fur) and more about the detail required to solve the problem (e.g. the number of buttons). You could provide teddy bear outlines to support children in thinking about the relevant details.
- Let the students solve the problem in pairs. As they work, encourage them to explain what they are doing.
- Share solutions.
Extensions
If there are seven bear cubs in the family how many buttons would Mother Bear need to buy?
If Mother Bear has bought 24 buttons, how many coats, each with three buttons will she make?
Solution
15 (3..6..9..12..15)
The students may be able to skip count in threes to 15, or may group the buttons into 5 groups of 3 and then count in ones to 15.
Solution to the Extensions
21 (3..6..9..12..15..18..21)
The students may be able to skip count in threes to 21, or may group the buttons into 7 groups of 3 and then count in ones to 21.
The students may make 8 piles of 3 buttons and state 8 coats.