MSTAR Practice Worksheet

Lesson 6-6: Identify Equivalent Algebraic Expressions

Grade 6 Mathematics · Standard 6.AT.7

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

Which expression is equivalent to 4x + 3x?

A7x
B7x²
C12x
D43x

Question 2Selected response · 1 point

Which expression is equivalent to 2(m + 5)?

A2m + 10
B2m + 5
C7m
Dm + 10

Question 3Selected response · 1 point

Which property is shown: 3(x + 7) = 3x + 21?

ACommutative
BDistributive
CAssociative
DIdentity

Question 4Selected response · 1 point

Simplify: 5n + 2n

A7n
B7n²
C10n
D52n

Question 5Selected response · 1 point

Producer A wrote 2(x + 3) for a beat's cost. Which expression is equivalent?

A2x + 6
B2x + 3
C2x + 5
Dx + 6

Question 6Selected response · 1 point

A track stacks 3x and then one more x. Which expression is equivalent to 3x + x?

A3x²
B3x
C4x
D4

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

Which expression is equivalent to 4(x + 3)?

Fill in the bubble next to the one best answer.

A4x + 12
B4x + 3
C7x
Dx + 12

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 4 by each term inside the parentheses: 4 · x + 4 · 3 = 4x + 12. Testing x = 2 gives 4(2 + 3) = 20 and 4(2) + 12 = 20, so the two expressions match.
BMultiply only the first term inside the parentheses and copy the second term: 4x + 3.
CAdd 4 and 3 because both are numbers, then attach the variable: 7x.
DMultiply only the second term inside the parentheses and copy the first term: x + 12.

Question 8Written response · 2 points

Type II Reasoning: Testing Only One Value

Priya claimed that 2x + x and 2x² are equivalent expressions. Her only check was x = 0. She wrote: 2(0) + 0 = 0 and 2(0)² = 0. Because both results were 0, she said the expressions are equivalent.

Explain Priya's misconception and give the correct simplified form of 2x + x.

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

A student says 2x + 3 and 5x are equivalent because both equal 5 when x = 1. Is the student correct? Explain why testing one value is not enough to prove equivalence, and find a value of x where they give different results.

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