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9th grade · Math · Unit 7 of 17

Expressions

Build, compare and match

What your child practices

Writing an expression for a pattern or a sentence, deciding which expressions are equivalent, expanding brackets, and collecting like terms.

Minnesota K-12 Academic Standards benchmark: 9.3.5.8; 9.3.5.7 · writing expressions in equivalent forms

How we explain it

Children can open this short lesson before they practice.

  1. An expression uses letters and numbers: 3n + 2.
  2. Equivalent expressions have the same value for every number.
  3. Expand with the distributive property: 2(x + 3) = 2x + 6.

Example: Expand 3(x + 4). 3 × x = 3x. 3 × 4 = 12. Answer: 3x + 12

Expressions in Minnesota

In the Minnesota K-12 Academic Standards, this is unit 7 of 17 in 9th grade Math, after Number Sets and before Lines & Intersections.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Minnesota Department of Education (MDE)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Which expression gives the number of tiles in figure n?

    Figure nTiles
    18
    214
    320
    426
    • 6n − 2
    • 6n + 2
    • 8n
    • 2n + 6

  2. Question 2

    Figure n in a pattern uses 3n + 6 tiles. How many tiles does figure 18 use?

    answer box

  3. Question 3

    Which expression is NOT equivalent to 3x + 12?

    • x + 2x + 12
    • 3(x + 12)
    • 3(x + 4)
    • 12 + 3x

  4. Question 4

    Ana has 9 fewer than 5 times the number of cards Leo has. If Leo has n cards, which expression gives the number Ana has?

    • 5n − 9
    • 9n − 5
    • 9 − 5n
    • 5(n − 9)

  5. Question 5

    Jay has 2 more than 3 times the number of stickers Sam has. If Sam has n stickers, which expression gives the number Jay has?

    • 5n
    • 3(n + 2)
    • 3n + 2
    • 2n + 3

  6. Question 6

    Which expression is equivalent to 3(x + 5)?

    • 3x + 5
    • x + 15
    • 3x + 8
    • 3x + 15

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