# Number Duel — Order of operations Puzzle | Mathallery

Source: https://mathallery.com/games/duel/

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# Number Duel

Order of operations · 30 levels

Play spell cards to drop the monster to exactly 0.

## How to play

- The monster's health is a number. Tap a card (or drag it onto the monster) to cast it on that number: −5, ÷3, ×2, +4 …
- Win by landing health on exactly 0. A Strike bigger than the health is overkill and can't be played; Split only works when it divides evenly.
- Later: cards cost mana (blue gems), a shield soaks up the next Strike, ⇄ Mirror swaps the digits (42 → 24) and √ Wither takes a square root.

Work backwards: the last card must be a Strike equal to the health left. From level 20 there is exactly one winning order.

[Open Number Duel](https://mathallery.com/#/play/duel/1)

Teeter, Tint and Echo Heist are free starters. Other games unlock through earned game choices or permanent packs. Your progress stays in the browser; optional sign-in saves it to your website account.