Cambridge questions are written in precise mathematical English. If you know exactly what product, difference, justify and estimate ask you to do, you will not lose marks answering the wrong question.
| Term | What it means | Example |
|---|---|---|
| sequence | A list of numbers in a definite order. | 3, 7, 11, 15, … |
| term | One of the numbers in a sequence. | The 2nd term is 7. |
| term-to-term rule | How to get from one term to the next. | “Add 4”. |
| first term | The number a sequence starts at. | 3 in 3, 7, 11. |
| common difference | The constant gap in a linear sequence. | 4 in 3, 7, 11. |
| linear sequence | One whose gap is always the same. | 5, 9, 13, 17. |
| nth term | A rule giving any term from its position. | 4n − 1. |
| position | Where a term sits; n = 1 is the first. | n = 10 for the 10th. |
| coefficient | The number multiplying a letter. | 4 in 4n − 1. |
| substitute | Put a number in place of a letter. | n = 3 gives 11. |
| function | A rule turning each input into one output. | y = 2x + 1. |
| function machine | A diagram of a function as operations in order. | [ × 2 ] → [ + 1 ]. |
| input | The number that goes in. | x. |
| output | The number that comes out. | y. |
| inverse | The operation that undoes another. | ÷ 5 undoes × 5. |
| mapping diagram | Arrows from each input to its output. | 1 → 5, 2 → 9. |
| square numbers | 1, 4, 9, 16, … from squaring. | 5² = 25. |
| triangular numbers | 1, 3, 6, 10, … with gaps growing by 1. | The next is 15. |