Purpose

The purpose of this activity is to engage students in solving a problem involving fractions.

Achievement Objectives

NA4-1: Use a range of multiplicative strategies when operating on whole numbers.

NA4-3: Find fractions, decimals, and percentages of amounts expressed as whole numbers, simple fractions, and decimals.

Description of Mathematics

The background knowledge and skills that need to be established before and/or during this activity are outlined in the diagram below:

Click to show example questions for each heading

This activity may be carried out with step by step guidance, or by allowing the student to follow their own method of solution. The approach should be chosen in sympathy with students' skills and depth of understanding.

Activity

I am twice my brother's age and one fifth my mother's age.

My dad is older than mum by half my brother's age.

All our ages are whole numbers.

I go to school but my brother doesn't yet.

How old are we?

### The arithmetic approach (show more)

- The student is able to form and solve appropriate equations in order to solve the problem.

### The procedural algebraic approach (show more)

- The student is able to form and solve appropriate equations in order to find the solution set for the problem.

### The conceptual approach (show more)

- The student is able to find the solution set to a problem, using the patterns and relationships described.
- The students are encouraged to work with natural (counting) numbers for trials of scale factors, generalising by using n.

Attachments

HowOld!_full.pdf585.37 KB

HowOld!_arithmetic.pdf203.49 KB

HowOld!_conceptual.pdf203.87 KB

HowOld!_procedural.pdf205.6 KB