Grill Master Guide Teacher ResourceGrill Master Guide Teacher Resource Lesson: The Perfect Pair (Least Common Multiple) Objective Students will distinguish between common multiples and the Least Common Multiple (LCM) and explain why the 'Least' is mathematically significant. Pacing 45 Minutes (5 Warm-up, 10 Video, 20 Activity, 10 Reflection) Materials BBQ Matchmaker Slides Venn Diagram Grill Worksheets Number Cards (1-50) Sizzling Reflections Journal 5m Warm-up: Mystery Number Pose the riddle: "I am a multiple of both 3 and 4. Who am I?" Encourage students to find multiple answers (12, 24, 36, 48). Note that all of these are "Common Multiples". 10m Video Analysis: The BBQ Dilemma Watch the video Introduction to LCM. Focus specifically on the timestamp 3:00-3:50. Discussion Prompts Pause at 3:05: "Before we see the answer, which numbers appear in both lists for 2 and 4?" Pause at 3:30: "We found 4 and 8 are both common. If Lucy wants to spend the least amount of money and have the fewest leftovers, which should she pick?" 20m Activity: The Venn Diagram Grill Students use the "Venn Diagram Grill" and "Number Cards" to find the LCM of specific pairs. Pairs for Practice: 3 and 5 (LCM: 15) 4 and 6 (LCM: 12) 5 and 10 (LCM: 10) Key Step: Students must circle the SMALLEST number in the intersection. This is the LCM. All others are "Common Multiples". 10m Reflection: The Infinite Problem Students respond to the "Sizzling Reflections" prompt in their journals. "Why can't we find a Greatest Common Multiple (GCM)? How is this different from finding a Greatest Common Factor (GCF)?" Chef's Notes (Teacher Tips) Misconception: Students often think the LCM must be bigger than both numbers. Use the 2 and 4 example to show the LCM can be one of the original numbers. Vocabulary: Reiterate that "Multiple" sounds like "Multiply"—they grow bigger. "Factors" are what we "Fact-ure" (break down)—they are smaller.
BBQ Matchmaker SlidesThe Perfect Pair A Grill Master's Guide to LCM Warm-up: Mystery Number "I am a multiple of both 3 and 4. Who am I?" Hint 1 There is more than one answer! Hint 2 Keep counting by 12s... The BBQ Problem How many packs of hot dogs and buns should Lucy buy? Hot Dogs: Packs of 3 Buns: Packs of 4 Watch & Learn Embedded media The "Least" Discussion "We found that 4 and 8 are both common multiples of 2 and 4..." Why is 4 the answer? If Lucy bought 8 of each, she would have enough. But what's the benefit of picking 4? Definition Least Common Multiple The smallest number that is a multiple of both. Fire Up the Grill Use your Venn Diagram Grill and Number Morsels to find the LCM for your pairs. The Goal Find ALL common multiples in the intersection, then circle the LEAST (the LCM)! Food for Thought Journal Entry "Why can't we find a Greatest Common Multiple?" Think about how multiples are made. Do they ever stop growing?
Venn Diagram Grill WorksheetThe Venn Diagram Grill Finding the Perfect Pair (LCM) Name Date Instructions: For each pair of numbers, list their multiples inside the circles. Multiples that appear in both lists go in the sizzling intersection. Once you're done, circle the smallest number in that intersection—that's your Least Common Multiple (LCM)! Round 1: 3 & 5 Multiples of 3 Multiples of 5 Common Multiples LCM: Round 2: 4 & 6 Multiples of 4 Multiples of 6 Common Multiples LCM: Round 3: 5 & 10 Multiples of 5 Multiples of 10 Common Multiples LCM: Grill Space (Work Area)
Multiple Morsels Number CardsMultiple Morsels Cut these out to place on your Venn Diagram Grill! 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Cut along the lines to create your "Morsel" cards. Use these to find matches on your Venn Diagram Grill worksheet. Remember: multiples are the results of multiplying your starting number!
Sizzling Reflections JournalSizzling Reflections Post-Grill Journal Entry Name Date 1 The Infinite Grill Why can't we find a Greatest Common Multiple (GCM)? Explain using what you know about how multiples are created. 2 Multiples vs. Factors How is finding a Least Common Multiple different from finding a Greatest Common Factor? 3 Chef's Special Can you think of one other real-world scenario (besides BBQ items) where someone might need to find a Least Common Multiple?
Venn Diagram Grill Answer KeyAnswer Key Teacher Resource Venn Diagram Grill Activity Round 1: Multiples of 3 and 5 Multiples of 3 (Left): 3, 6, 9, 12, 18, 21, 24, 27, 33, 36, 39, 42, 48 Multiples of 5 (Right): 5, 10, 20, 25, 35, 40, 50 Intersection (Common Multiples): 15, 30, 45 Least Common Multiple: 15 Round 2: Multiples of 4 and 6 Multiples of 4 (Left): 4, 8, 16, 20, 28, 32, 40, 44 Multiples of 6 (Right): 6, 18, 30, 42 Intersection (Common Multiples): 12, 24, 36, 48 Least Common Multiple: 12 Round 3: Multiples of 5 and 10 Multiples of 5 (Left): 5, 15, 25, 35, 45 Multiples of 10 (Right): (Empty - all are in intersection) Intersection (Common Multiples): 10, 20, 30, 40, 50 Least Common Multiple: 10 Note: Students should circle the smallest number in the common multiples list.
