Definition
Input-output table
An input-output table lines up each input with the output made by the same rule.
| Input | Output |
|---|---|
| 1 | 3 |
| 2 | 5 |
| 3 | 7 |
| 4 | 9 |
What it means
Read one row at a time. The input is the value you start with, and the output is the value the rule makes. Keep each pair lined up so you do not swap partners. Then check the whole table: the same rule must work for every row, not just one or two.
Remember it
One row, one pair; one rule for the whole table.
Example
Inputs 2, 5, and 8 are paired with outputs 7, 16, and 25. The rule “multiply by 3, then add 1” works every time: 2 × 3 + 1 = 7, 5 × 3 + 1 = 16, and 8 × 3 + 1 = 25.
Watch for
Two nearby lists are not an input-output table unless the pairing is clear. A row or column position must show which output belongs to each input.
Common mix-up
Do not invent a different operation for each row. A valid table rule must fit every displayed input-output pair.
Exact meaning
An input-output table displays ordered input-output pairs in aligned rows or columns. Each input is paired with its corresponding output, and one stated or discoverable rule must fit every pair in the table.