Teaching scaling can be difficult because students are required to think abstractly.
There are a few important things your students need to understand in order to be successful with scaling fractions.
By clarifying these concepts, you can help your students better understand scaling.
1. An object can be scaled UP or DOWN
When teaching scaling, draw three images on the board.
First, draw your medium-sized image. This can be any image, such as a simple heart. Then draw the same image, but smaller. Below it, write scaled down.
Next, draw the largest image, and beneath it write scaled up. Explain to your students that scaling can go up and down.
2. Is the fraction greater or less than one whole?
Understanding if a fraction is greater or less than one whole is CRUCIAL to understanding scaling.
Practice this concept many times before you even introduce scaling!
You can do this by sorting fractions as being less than or greater than one whole as part of your math routine.
If your students do not understand how to tell if a fraction is greater or less than one whole, they will have trouble comprehending scaling.
Make sure your students master this skill before teaching scaling.
3. The rules for scaling
The most important concept for students to learn is multiplication as scaling.
When you multiply by a fraction that is LESS THAN ONE WHOLE, the size will be scaled down.
When you multiply by a fraction that is GREATER THAN ONE WHOLE, the size will be scaled up.
By knowing this concept, students can determine if their answers are reasonable.
What happens when you multiply by a fraction equivalent to one whole?
It’s important for students to understand the value of fractions, especially fractions that are equivalent to one whole.
Would the product be greater than, less than, or equal to the whole number when you multiply it by a fraction equivalent to one whole? (Example: 3/3 x 6 would be EQUIVALENT to 6 because 3/3 equals one whole.)