If the order of two numbers in a calculation does not affect the result, the calculation operation is said to be commutative.

Addition and multiplication are commutative.

• 6 + 3 = 3 + 6
  (Both sides have a sum of 9.)
  
  
• 6 × 3 = 3 × 6
  (Both sides have a product of 18.)

Subtraction and division are generally NOT commutative.

• 6 − 3 ≠ 3 − 6
  (6 − 3 = 3, whereas 3 − 6 = −3)
  
  
• 6 ÷ 3 ≠ 3 ÷ 6
  (6 ÷ 3 = 2, whereas 3 ÷ 6 = 0.5)