Question
Find the following values without a calculator.

  1. 18 + _____ = 31
  2. 24 + _____ = 58
  3. 74 + _____ = 82
  4. 87 + _____ = 173
4 m
(a)

Click button first when a symbol is required. X

(b)

Click button first when a symbol is required. X

(c)

Click button first when a symbol is required. X

(d)

Click button first when a symbol is required. X

Find the following values without a calculator.

  1. 18 + _____ = 31
  2. 24 + _____ = 58
  3. 74 + _____ = 82
  4. 87 + _____ = 173