| Clue | Source | Date |
|---|---|---|
| Harold Davenport's <i>The Higher Arithmetic </i>(first published in 1952) is a major text about this branch of maths | The Times Specialist Sunday | 01 Feb 2026 |
| Studying figures of miners, nearly all allocated place round track | ||
| Study of integers and their properties | The Times Concise | 22 Nov 2017 |