Solve equations using properties

Key Notes :

  • Identity property: Adding zero does not change a number.
  • Distributive property: You can multiply a sum by multiplying each addend separately. The distributive property works with subtraction, too.

Learn with an example

🎯 What value of c makes this addition number sentence true?

Hint: Use properties of addition.

0 + 92 = c

c = ________

  • To find c, use properties of addition to make both sides of the equation look the same.
  • The identity property says adding zero does not change a number.
    0+92 = c
    92 = c Apply the identity property
    Now match up the two sides of the equation.
    92 = c
    So, c = 92

🎯 What value of u makes this multiplication number sentence true?

Hint: Use properties of multiplication.

23 · (37 − 30) = 23 · 37 − 23 · u

u = _______

  • To find u, use properties of multiplication to make both sides of the equation look the same.
  • The distributive property says you can multiply a sum or difference by multiplying each term separately.
  • 23 · (37 − 30) = 23 · 37 − 23 · u
  • 23 · 37 − 23 · 30 = 23 · 37 − 23 · u Apply the distributive property
  • Now match up the two sides of the equation.
  • 23 · 37 − 23 · 30 = 23 · 37 − 23 · u
  • So, u = 30.

🎯 What value of d makes this addition number sentence true?

Hint: Use properties of addition.

93 + d = 100 + 93

d = ________

  • To find d, use properties of addition to make both sides of the equation look the same.
  • The commutative property says you can add numbers in any order and get the same sum.
  • 93 + d = 100 + 93
  • 93 + d = 93 + 100 Apply the commutative property
  • Now match up the two sides of the equation.
  • 93 + d = 93 + 100
  • So, d = 100.

Let’s practice!🖊️