Visualising Common Denominators
Learning Objective
At the end of the lesson you will be able to explain and use pictures to find a common denominator for fractions.
Items in this lesson
Learning Objective
At the end of the lesson you will be able to explain and use pictures to find a common denominator for fractions.
What do you already know about finding common denominators?
What Is a Denominator?
The denominator is the number below the fraction line. It shows how many equal parts make a whole.
Why Find a Common Denominator?
To add or compare fractions, their denominators must be the same. This makes the parts equal.
Pictorial Example – Different Denominators
Imagine 1/2 (one-half) and 1/3 (one-third). The sizes of the pieces are not equal yet. Let's see it!
Making Denominators the Same
We turn each shape into equal parts. For 1/2 and 1/3, we use 6 parts (sixths), so both pies are split into 6 slices.
Schematic Drawing – Step by Step
Draw two circles. Split one into 2, the other into 3. Then redraw both, splitting each into 6, so pieces match.
Practical Example: 2/5 and 1/2
Multiply 5 by 2 = 10. The common denominator is 10.
Show both fractions as tenths (2/5 = 4/10 and 1/2 = 5/10). Colour the parts to see the answer visually.
Step 2: Draw Fractions
Step 1: Find the Common Denominator
Summing Up
A common denominator helps compare or add fractions. Using drawings helps us see why and how this works.
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.
