Lesson 18: Using Common Multiples and Common Factors | Unit 7: Rational Numbers

Open Ended

Mai, Clare, and Noah are making signs to advertise the school dance. It takes Mai 6 minutes to complete a sign, it takes Clare 8 minutes to complete a sign, and it takes Noah 5 minutes to complete a sign. They keep working at the same rate for a half hour. Will Mai and Clare complete a sign at the same time? Explain your reasoning.

Open Ended

Mai, Clare, and Noah are making signs to advertise the school dance. It takes Mai 6 minutes to complete a sign, it takes Clare 8 minutes to complete a sign, and it takes Noah 5 minutes to complete a sign. They keep working at the same rate for a half hour. Will Mai and Noah complete a sign at the same time? Explain your reasoning.

Open Ended

Mai, Clare, and Noah are making signs to advertise the school dance. It takes Mai 6 minutes to complete a sign, it takes Clare 8 minutes to complete a sign, and it takes Noah 5 minutes to complete a sign. They keep working at the same rate for a half hour. Will Clare and Noah complete a sign at the same time? Explain your reasoning.

Open Ended

Mai, Clare, and Noah are making signs to advertise the school dance. It takes Mai 6 minutes to complete a sign, it takes Clare 8 minutes to complete a sign, and it takes Noah 5 minutes to complete a sign. They keep working at the same rate for a half hour. Will all three students complete a sign at the same time? Explain your reasoning.

Multiple Choice

What is the product of 12 and 8?

• 80
• 72
• 96
• 100

Multiple Choice

Find the greatest common factor of 12 and 8.

• 4
• 8
• 6
• 2

Multiple Choice

What is the least common multiple of 12 and 8?

• 24
• 20
• 32
• 16

Multiple Choice

Find the product of the greatest common factor and the least common multiple of 12 and 8.

• 96
• 72
• 24
• 48

Multiple Choice

What do you notice about the answers to question 1 and question 4?

• The answers are both incorrect.
• The answers are related in theme.
• The answers are completely unrelated.
• The answers are from different subjects.

Multiple Choice

Choose 2 other numbers, and repeat the previous steps. Do you get the same results?

• Yes, you will always get the same results.
• No, you may not get the same results.