Commutative Property

Definitionnoun phrase

What is the commutative property in math?

The commutative property says that changing the order of the numbers does not change the result of adding or multiplying them: a + b = b + a and a × b = b × a. For example, 4 + 9 = 9 + 4 and 3 × 5 = 5 × 3. Subtraction and division are not commutative.

In Spanish
propiedad conmutativa
Also called
commutative law, order property, commutative property of addition, commutative property of multiplication
How to say it
kuh-MYOO-tuh-tiv
Grade level
K-5
Grade 1Grade 3Grade 6Algebra 1CCSS 1.OA.B.3CCSS 3.OA.B.5CCSS 6.EE.A.3ASVABGEDTABEHiSETACCUPLACER

Commutative Property in a picture

Commutative property: order does not change a sum or productA 3 by 5 array of green dots turned into a 5 by 3 array of blue dots; both have 15 dots, so 3 times 5 equals 5 times 3. Below, a table shows that 4 plus 9 equals 9 plus 4 and 6 times 2 equals 2 times 6, but 9 minus 4 is not 4 minus 9 and 6 divided by 2 is not 2 divided by 6.Turn the array: same total3 rows of 55 rows of 3turn3 × 5 = 15 = 5 × 3CommutativeNot commutative4 + 9 = 9 + 49 − 4 = 513 = 13 ✓4 − 9 = −5 ✗6 × 2 = 2 × 66 ÷ 2 = 312 = 12 ✓2 ÷ 6 = 1/3 ✗
Turning an array does not change how many dots it has, so 3 × 5 = 5 × 3. Swapping works for + and ×, never for − or ÷.

Formal definition and notation

An operation · is commutative on a set if a · b = b · a for all a and b in the set. For all real numbers a and b, addition and multiplication are commutative: a + b = b + a and a · b = b · a. Subtraction and division are not: in general a − b ≠ b − a and a ÷ b ≠ b ÷ a.

Symbol Read it as Meaning
a + b = b + a a plus b equals b plus a commutative property of addition
ab = ba a times b equals b times a commutative property of multiplication

Key facts

  • The name comes from “commute”, to move or travel: the numbers swap places.
  • It halves the facts to memorize: knowing 6 × 8 = 48 gives 8 × 6 = 48 for free.
  • It works for fractions, decimals, negatives and variables: −2 + 7 = 7 + (−2) and 3x = x · 3.
  • Rewrite subtraction as adding a negative to reorder safely: 10 − 4 + 6 = 10 + 6 + (−4) = 12.
  • The commutative property changes order; the associative property changes grouping.

Try it: swap the length and width

Interactive

The rectangle is 6 by 3. Drag the corner to make it 3 by 6: the area stays 18 square units, which is the commutative property of multiplication.

This interactive needs JavaScript. The worked examples below show the same ideas step by step.

Commutative Property examples, step by step

Example 1: Fill in the blank

Warm-up

Fill in the box: 27 + 58 = 58 + □.

  1. The commutative property swaps the addends: a + b = b + a.
  2. The missing number is 27.
  3. Check: both sides equal 85.

Answer: The box is 27.

Example 2: Reorder to compute fast

Core

Compute 25 × 17 × 4 mentally.

  1. Swap the last two factors: 25 × 4 × 17.
  2. 25 × 4 = 100.
  3. 100 × 17 = 1,700.

Answer: 25 × 17 × 4 = 1,700

Example 3: Which property?

Test-style

Which property justifies 5x + 3 = 3 + 5x?

  1. The two terms 5x and 3 trade places.
  2. Nothing is regrouped and nothing is distributed.
  3. Order changing with addition is the commutative property of addition.

Answer: The commutative property of addition.

Common mistakes

✗ Mistake15 − 6 = 6 − 15, because order does not matter.
✓ Instead15 − 6 = 9 but 6 − 15 = −9.

The commutative property holds for addition and multiplication only.

✗ Mistake12 ÷ 3 = 3 ÷ 12
✓ Instead12 ÷ 3 = 4 but 3 ÷ 12 = 14.

Division is not commutative; swapping the numbers gives the reciprocal.

✗ MistakeCalling (2 + 3) + 4 = 2 + (3 + 4) the commutative property.
✓ InsteadThat is the associative property: the order 2, 3, 4 is the same and only the parentheses move.

Commutative means the numbers change places; associative means the grouping changes.

Not to be confused with

Commutative Propertyvs.Associative property

Associative regroups without reordering: (1 + 2) + 3 = 1 + (2 + 3). Commutative reorders: 1 + 2 = 2 + 1.

Commutative Propertyvs.Distributive property

Distributive links multiplication and addition: 3(4 + 5) = 3 × 4 + 3 × 5. Commutative uses one operation at a time.

Quick check: 3 questions

Question 1 of 3

Which equation shows the commutative property?

Show answer and explanation

Answer: C. Only 9 × 4 = 4 × 9 swaps the order of two numbers. 7 × 1 and 8 + 0 are identity properties, and 2(3 + 5) is the distributive property.

Question 2 of 3

Which operation is commutative?

Show answer and explanation

Answer: B. Multiplication is commutative: 2 × 7 = 7 × 2. Subtraction (7 − 2 ≠ 2 − 7) and division (8 ÷ 2 ≠ 2 ÷ 8) are not.

Question 3 of 3

If a + 14 = 14 + 23, what is a?

Show answer and explanation

Answer: D. By the commutative property, 23 + 14 = 14 + 23, so a = 23. 37 is the sum, 14 is already in place, and 9 is 23 − 14.

Commutative Property: frequently asked questions

Is subtraction commutative?

No. 10 − 3 = 7 but 3 − 10 = −7, so swapping the numbers changes the answer. Division is not commutative either: 10 ÷ 2 = 5 but 2 ÷ 10 = 0.2. To reorder a subtraction safely, write it as adding a negative: 10 − 3 = 10 + (−3) = (−3) + 10.

What is the difference between the commutative and associative properties?

The commutative property changes the order of the numbers: 4 × 7 = 7 × 4. The associative property keeps the order but changes the parentheses: (4 × 7) × 2 = 4 × (7 × 2). A memory trick: to commute is to travel, so the numbers move; to associate is to group with friends, so the parentheses change.

Practice and tools

Sources

  1. Common Core State Standards, Grade 1 Operations and Algebraic Thinking (1.OA.B.3)
  2. Common Core State Standards, Grade 3 Operations and Algebraic Thinking (3.OA.B.5)
  3. OpenStax, Prealgebra 2e, 7.2 Commutative and Associative Properties

Updated November 2026·Reviewed by the Effortless Math team·Standards: CCSS 1.OA.B.3, CCSS 3.OA.B.5, CCSS 6.EE.A.3

Cite this entry

Effortless Math Team. “Commutative Property.” Effortless Math Dictionary. Updated November 2026. https://www.effortlessmath.com/math-dictionary/commutative-property/

Flashcard

TermCommutative Propertya + b = b + a
DefinitionOrder does not change a sum or product: 4 + 9 = 9 + 4, 3 × 5 = 5 × 3. Not true for subtraction or division.
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