Lesson Plan: GCF & LCM

Note: Make sure all students have a calculator for this lesson.
  1. (5 min) Mental Math
    1. How many ways can I reorder the letters in the word "MATH"? [24]
    2. What is one half of one half of one half? [1/8]
    3. Multiply 2/3 by 1/4 and reduce [1/6]
    4. Start with 33, add 55, then divide by 8 [11]
    5. Which is larger, 1/4 or .245? [1/4]

  2. Pass out the GCF-LCM handout
  3. (10 min) Follow the handout to discuss greatest common factor (GCF)
    • Discuss the problem (12 and 8) in the handout.
    • Don't discuss the equation on that handout for finding the GCF given the LCM.
    • Have the students do problems 1-6 in the in-class page 1
  4. (10 min) Follow the handout to discuss the least common multiple (LCM)
    • Discuss the problem (6 and 8) in the handout.
    • Don't discuss the equation on that handout for finding the LCM given the GCF.
    • Have the students do problems 1-6 in the in-class page 2
  5. (10 min) Discuss the GCF-LCM equation and how it applies to the GCF and the LCM (follow the handout)
  6. (20 min)
    • Do the in-class page 1 problems 7-12 (equation problems)
    • Do the in-class page 2 problems 7-12 (equation problems)
    • Do the in-class page 3 problems (1-3) (word problems)
  7. Hand out homework when students complete the in-class