LCM and GCF Word Problems

Which strategy helps in solving word problems involving LCM and GCF?

• Write and Erase

• Read to Prepare, Solve, and Check

• Jump and Run

• Sing and Dance

When do we use the least common multiple (LCM)?

• When dividing items

• When finding a shared time or repeated event

• When adding numbers

• When subtracting numbers

In a gym class, one group switches every 12 minutes and another every 18 minutes. When will both groups switch at the same time?

• 24 minutes

• 30 minutes

• 36 minutes

• 48 minutes

#3) A teacher has 45 markers and 30 crayons.
What is the greatest number of boxes she can use to pack them with the same number of each item?

Is this a GCF or LCM problem? How do you know?
(Remember to cite your evidence!)

#3) A teacher has 45 markers and 30 crayons.
What is the greatest number of boxes she can use to pack them with the same number of each item?

What is the answer? __ boxes

#4) Mrs. Henry waters her front yard every 6 days and her backyard every 8 days.
If she watered both today, in how many days will she water both again on the same day?

Is this a GCF or LCM problem? How do you know?
(Remember to cite your evidence!)

#4) Mrs. Henry waters her front yard every 6 days and her backyard every 8 days.

If she watered both today, in how many days will she water both again on the same day?

What is the answer? __ days

#5) A school has 120 chairs and 150 desks.
They want to set up classrooms with the same number of chairs and desks in each.
What is the greatest number of classrooms they can set up?

Is this a GCF or LCM problem? How do you know?
(Remember to cite your evidence!)

#5) A school has 120 chairs and 150 desks.

They want to set up classrooms with the same number of chairs and desks in each.

What is the greatest number of classrooms they can set up?

What is the answer? __ classrooms

#6) Two buses leave the station at the same time.

One returns every 20 minutes, and the other every 30 minutes.

After how many minutes will both buses be at the station again at the same time?

Is this a GCF or LCM problem? How do you know?
(Remember to cite your evidence!)