A fascinating game that combines arithmetic and logic, perfect for older children and adults.

From the All Eyes on Me retro party-game collection, this old-fashioned favourite brings simple fun to a modern gathering.

At a glance

Players: 2+ players.
You will need: Paper and pencils.
Cost: Free instructions; use items you already have. Optional props or prizes may cost extra.

How to play

1. Try The Magic Nine: multiply 9 by a positive whole number. Add the result’s digits, then keep adding until one digit remains: it will be 9. Example: 9 × 27 = 243; 2 + 4 + 3 = 9.
2. Set the Century Puzzle: keep the digits 1–9 in order and insert plus or minus signs, allowing joined digits, to make 100.
3. Give players five minutes to find a solution before sharing this example: 123 − 45 − 67 + 89 = 100.
4. Try a Number Reveal: choose a number, double it, add 10, halve the result and subtract the starting number. The answer is always 5.
5. Invite players to explain why each trick works. Score for clear explanations as well as speed.

Host’s tip

The repeated digit-addition step matters: a first digit sum can be 18 or 27 rather than 9.

Agree on the rules before you start. Guests can join, adapt a movement or pass; use points or optional playful challenges wherever the retro rules mention forfeits.

About this retro collection

Refreshed from the original All Eyes on Me party-game collection and supplied game notes, with language and practical adaptations for today’s celebrations. View the archived collection.

Browse all FREE Party Games