When I teach my students, I show them connections between different things, and I do this visually. Why? Because seeing connections between related ideas and procedures is a powerful way to develop a deep understanding of what you are learning.
I recently had the chance to do this with Year 11 students studying the topic consumer mathematics. The topic involves working with percentages, including interest, inflation, markup, profit/loss and GST.
Today, I want to share how I used two different visuals to help students understand the mathematical procedures involved with the GST:
- The Bar Model
- The Triangle Model
You can also use these as learning strategies when you do similar problems yourself.
The Bar Model
I started with the bar model, which is a simple way of visually representing percentage problems. In a basic problem, you use 3 bars, one to represent:
- A given number
- The percentage
- The answer
Note: Sometimes (b) and (c) are the same, but including (c) helps students think about what the question is asking them to answer.
Piper’s Problem Using the Bar Model
Piper received an invoice for $500 ex-GST. How much does Piper need to pay, including the GST?
The Bar Model helps to show:
- How the bits of information you know are related
- What the question is asking you to find
The Triangle Model
I then introduced the triangle model to visually show relationships between the elements. This included inverse relationships.
The Triangle Model helps to visually show mathematical relationships.
