MSTAR Practice Worksheet

Lesson 6-12: Least Common Multiple

Grade 6 Mathematics · Standard 6.NOS.4

Name: Date:

These are MSTAR-style questions written for this curriculum to rehearse the format. They are not official Maryland assessment items. MSTAR — Maryland's new state test, first given in spring 2027 — uses the same kinds of questions you see here: selected response, select-all, two-part evidence questions, and written responses.

Part A — Skills Check

Warm up with the lesson's core skills — one best answer each.

Question 1Selected response · 1 point

What is the LCM of 3 and 5?

Question 2Selected response · 1 point

What is the LCM of 6 and 8?

Question 3Selected response · 1 point

What is the LCM of 4 and 10?

Question 4Selected response · 1 point

What is the LCM of 2 and 7?

Question 5Selected response · 1 point

Two rovers leave the space station at 8:00 AM. Rover A returns every 15 minutes and Rover B returns every 20 minutes. When is the next time both rovers are at the station together?

A8:30 AM (30 minutes later)
B8:40 AM (40 minutes later)
C9:00 AM (60 minutes later)
D9:20 AM (80 minutes later)

Question 6Selected response · 1 point

On the space station, the air filter runs every 4 min and the water pump runs every 6 min. They just ran together. In how many minutes do they run together again?

Part B — Test-Format Questions

These match the state test's formats: two-part questions, select-all, and written responses.

Question 7Two-part question

Part A

What is the least common multiple of 6 and 8?

Fill in the bubble next to the one best answer.

Part B

Answer Part A before Part B — Part B asks about your reasoning.

Which reasoning shows why your answer to Part A is correct?

AMultiply the two numbers together, 6 × 8 = 48, because the product is always the least common multiple.
BFind the largest number that divides both 6 and 8, which is 2.
CAdd the two numbers, 6 + 8 = 14.
DSkip count starting with the larger number: 8, 16, 24. Then skip count by 6: 6, 12, 18, 24. The first non-zero multiple in both lists is 24.

Question 8Written response · 2 points

Type II Reasoning: Multiplying Instead of Listing

Sofia found the least common multiple of 4 and 10 by multiplying the two numbers: 4 × 10 = 40. She wrote that the least common multiple of 4 and 10 is 40.

Explain Sofia's misconception and give the correct least common multiple.

Write your answer in complete sentences. Show or explain your mathematical thinking.

Part C — Show Your Thinking

Answer in writing, the way the state test's constructed responses work.

Question 9Written response · 2 points

You are making party favors. Glow sticks come in packs of 10 and bracelets come in packs of 4. What is the fewest of each you can buy so every favor has exactly one glow stick and one bracelet with none left over? Explain how the LCM solves this problem.

Write your answer in complete sentences. Show or explain your mathematical thinking.