LCM for Adding and Subtracting Fractions
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Objective
I can calculate the lowest common multiple to add and subtract fractions with unlike denominators.
Part 1 of 4
Warm-up video
Professor Dave Explains · 4:07Vetted channel
We don't generate video — this one is by Professor Dave Explains on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.
Part 2 of 4
Key concepts
3 concepts
- 1
When adding fractions with the same denominator, we only add the numerators, not the denominators.
- 2
To add fractions with different denominators, first find the least common multiple of the denominators.
- 3
To subtract fractions, find a common denominator, then subtract the numerators.
Part 3 of 4
Practice
10 questions
What is the first step in adding or subtracting fractions with different denominators?
Explain why it is necessary to find the least common multiple (LCM) when adding or subtracting fractions with different denominators.
Part 4 of 4
Exit ticket
Quick comprehension check
“Solve: ⅖ + ⅔. Show all steps, including finding the least common multiple.”
Sample answer included in the free materials
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