Addition and subtraction – balance equations – up to 20

Learn with an example

📗 Which number makes the equation true?

8 + 8 = 19 −

  • First, add 8 + 8:
  • 8 + 8 = 19 − ?
  • 16 = 19 − ?
  • Find the number that makes the subtraction number sentence true.
  • 19 − ? = 16
  • Subtract 16 from both sides:
  • 19 − ? − 16 = 16 − 16
  • 3 − ? = 0
  • Now, find the number that goes in the blank space. Remember, when a number is subtracted from itself, the difference is zero. The number in the blank space must be 3.
  • The missing number is 3.

📗 Which number makes the equation true?

10 − 3 =_____  + 1

  • First, subtract 10 − 3:
  • 10 − 3 = ? + 1
  • 7 = ? + 1
  • Decide which number makes the addition number sentence true. You can think of an addition fact you know, or you can subtract to find the answer.
  • The additional fact is:
  • 6 + 1 = 7
  • Do you remember this additional fact? If not, you can find the answer by subtracting.
  • Subtract:
  • 7 − 1 = 6
  • The missing number is 6.

📗 Which number makes the equation true?

12 − ____ = 4 + 8

  • First, add 4 + 8:
  • 12 − ? = 4 + 8
  • 12 − ? = 12
  • Subtract 12 from both sides:
  • 12 − ? − 12 = 12 − 12
  • 0 − ? = 0
  • Now, find the number that goes in the blank space. Remember, when a number is subtracted from itself, the difference is zero. The number in the blank space must be 0.
  • The missing number is 0.

Let’s practice!🖊️