Addition grid with tens
In an addition grid every cell is the sum of its row number and its column number: row 30 and column 40 give 70. Children fill the missing cells with multiples of 10 and notice the patterns across rows and columns.
How to solve this
- In a calculation grid, each cell is the product (or sum) of its row header and its column header.
- Find the row value and column value that belong to the empty cell, then apply the rule to fill it.
- Check by working in the opposite direction: the cell value split back by the header should return the other header.
Examples
20 + 30 = ?
50
47 - 12 = ?
35
Practice problems with answers
Solve these problems on paper or out loud, then check the answer key. The online practice and the printable worksheet give a new set every time.
+ | 10 | 20 | 40 20 | 30 | 40 | 60 60 | __ | 80 | 100 → missing cell = __
+ | 10 | 20 | 30 50 | 60 | __ | 80 70 | 80 | 90 | 100 → missing cell = __
+ | 10 | 30 | 50 10 | 20 | 40 | 60 50 | __ | 80 | 100 → missing cell = __
+ | 20 | 40 | 50 20 | 40 | 60 | __ 30 | 50 | 70 | 80 → missing cell = __
+ | 10 | 30 | 40 10 | __ | 40 | 50 20 | 30 | 50 | 60 → missing cell = __
+ | 10 | 20 | 30 20 | __ | 40 | 50 30 | 40 | 50 | 60 → missing cell = __
+ | 10 | 30 | 40 40 | 50 | 70 | 80 50 | 60 | 80 | __ → missing cell = __
+ | 10 | 40 | 50 20 | 30 | 60 | __ 50 | 60 | 90 | 100 → missing cell = __
Show answers
- 70
- 70
- 60
- 70
- 20
- 30
- 90
- 70