How to play Missing Subtrahend

  1. Look at the subtraction with the taken-away number hidden, such as 13 − ? = 7.
  2. Work out how much was taken away.
  3. Tap the answer from the five tiles below.
  4. A right answer scores and the next question appears.

For parents and teachers

Every answer in this game is between 1 and 9, and no number ever goes below zero. Finding the hidden number means seeing a subtraction as the gap between two numbers: 13 − ? = 7 is the distance from 7 up to 13. Children who understand subtraction this way usually remember the facts better than those who only count back. If a child is unsure, ask "how many more from 7 to make 13?" and let them count up once, then try the game again.