Students will learn how to find the GCD of whole numbers by listing factors, and the LCM by listing multiples.
Highest Common Factor and Lowest Common Multiple Part 1 by MathsMasterOrg
Do these Khan Academy exercises:
Next, give your students these challenges:
- 2018 Math Kangaroo Levels 3-4 Problem #17 by STEM4all
- 2021 Math Kangaroo Levels 1-2 Problem #18 by STEM4all
- 2019 Math Kangaroo Levels 5-6 Problem #28 by STEM4all
Conclude by leading this investigation:
House of Mirrors (symmetry, patterns, composite numbers)
by MathPickle
6.NS.B.4: Find the greatest common factor of two whole numbers less than or equal to 100 and the least common multiple of two whole numbers less than or equal to 12. Use the distributive property to express a sum of two whole numbers 1-100 with a common factor as a multiple of a sum of two whole numbers with no common factor. For example, express 36 + 8 as 4 (9 + 2).