Worksheet Library / Number Sense
Find Common Multiples in Lists
Focus: Common Multiples and Least Common Multiple. Use the worked example and teaching sequence below to explain the reasoning before independent practice.
Use New Numbers to make another set. Choose Worksheet or Answer Key, then use the worksheet’s Print button.
Teaching Notes
Focus: Common Multiples and Least Common Multiple. Use the worked example and teaching sequence below to explain the reasoning before independent practice.
Before You Begin
- List multiples of a number.
Teaching Steps for Parents and Teachers
- List positive multiples of both numbers.
- Find values that occur in both lists.
- Choose the least positive shared value.
Worked Examples
Find the least common multiple of 4 and 6.
- Multiples of 4: 4, 8, 12, 16, …
- Multiples of 6: 6, 12, 18, …
- The first shared positive value is 12.
Answer: 12
Common Mistakes and How to Help
The product is a common multiple, but it is not always the least one.
Can both numbers divide 12 exactly, and is there a smaller positive common multiple?
Questions to Check Understanding
- Can both numbers divide 12 exactly, and is there a smaller positive common multiple?
- Which step explains your answer?
- Can you apply the same reasoning when the numbers change?
Practice Advice
Work through the example together. Ask the learner to explain the first two problems, then try three independently. Review the first incorrect step before assigning more practice.
Next Practice
- Use New Numbers to practice the same skill with different values.
- If the learner needs help, return to the example and model each step before trying again.