In this worksheet, you have to find the missing numbers in addition grids.

Look at this grid.

+ |
1 |
2 |
3 |
4 |
5 |

1 |
|||||

2 |
6 | ||||

3 |
|||||

4 |
6 | ||||

5 |

It shows that 2 + 4 = 6 and 4 + 2 = 6

Now look at this grid.

+ |
1 |
2 |
3 |
4 |
5 |

1 |
|||||

2 |
3 | 6 | |||

3 |
|||||

4 |
6 | ||||

5 |
9 |

It now also shows that 2 + 1 = 3 and 5 + 4 = 9

__Example__

Complete the grid below to find the value of A.

+ |
1 |
2 |
3 |
4 |
5 |

1 |
2 | A | 4 | 5 | 6 |

2 |
A | 4 | 5 | 6 | 7 |

3 |
4 | 5 | 6 | 7 | 8 |

4 |
5 | 6 | 7 | 8 | 9 |

5 |
6 | 7 | 8 | 9 | 10 |

__Answer__

2 + 1 = 3 and 1 + 2 = 3

A is 3

+ |
1 |
2 |
3 |
4 |
5 |

1 |
2 | 3 | 4 | 5 | 6 |

2 |
3 | 4 | 5 | 6 | 7 |

3 |
4 | 5 | 6 | 7 | 8 |

4 |
5 | 6 | 7 | 8 | 9 |

5 |
6 | 7 | 8 | 9 | 10 |