Day 6 of 30
Find common denominators
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Learning Objective
Students will be able to find common denominators.
In this lesson, we'll explore how to find common denominators. Mathematical thinking develops logical reasoning and problem-solving abilities.
A common denominator is a number that two or more fractions can use as their denominator. To add or subtract fractions with unlike denominators, you need a common denominator first. The least common denominator (LCD) is the smallest common multiple of the denominators. For example, to add 1/4 + 1/6, the LCD is 12: change to 3/12 + 2/12 = 5/12. Finding common denominators lets you compare and compute with any fractions!
As you work through today's material, pay attention to the examples and try to identify the patterns or strategies being used. This will help you apply these concepts to new problems.
Take notes on key points and make connections to what you've already learned in previous lessons.
A mathematical question requiring analysis and solution
The result obtained by solving a problem
Instructions
Materials Needed
- Notebook
- Calculator (if needed)
- Graph paper
Find a common denominator for 1/3 and 1/4.
What is the LCD of 1/6 and 1/8?
Rewrite with common denominator: 1/4 and 1/3
Teaching Tip
For this age group: Balance direct instruction with collaborative activities. Allow students to explain their thinking and make connections to prior knowledge when exploring find common denominators.