addition table — Definition, Formula & Examples
An addition table is a chart that shows the sum of every pair of numbers in a set, usually the digits 0 through 9 (or 1 through 12). You find one number along the top row, another along the left column, and their sum appears where the row and column meet.
An addition table is a square array in which the entry in row and column equals , for all values of and in a specified set of whole numbers.
How It Works
Pick the first addend from the left column and the second addend from the top row. Trace your finger across the row and down the column until they intersect — that cell holds the sum. For example, row 4 and column 7 meet at 11, because . The table is symmetric: the cell at row 4, column 7 shows the same value as the cell at row 7, column 4, since addition is commutative. Practicing with the table helps you memorize basic addition facts and spot patterns, like every diagonal containing the same sum.
Worked Example
Problem: Use a 0–9 addition table to find 6 + 8.
Step 1: Find 6 in the left column of the table.
Step 2: Find 8 in the top row of the table.
Step 3: Move across row 6 and down column 8. The cell where they meet shows the sum.
Answer: The addition table gives 14.
Why It Matters
Memorizing basic addition facts is the foundation for mental math, multi-digit addition, and subtraction. An addition table also introduces the idea of reading data from rows and columns — the same skill you need for multiplication tables, spreadsheets, and coordinate grids.
Common Mistakes
Mistake: Confusing an addition table with a multiplication table and multiplying instead of adding.
Correction: Check the table's title or top-left corner. In an addition table, the cell at row 3, column 4 should read 7 (not 12). If it reads 12, you are looking at a multiplication table.