Arcana: Mental Math Tricks

Arcana teaches mental math the way a good language app teaches a language: one technique at a time, practised until it's fast, and brought back just before you'd forget it.

Every technique is a spell. Multiply any number by 11 in your head. Square 65 in two seconds. Work out a 15% tip before the waiter comes back. Name the day of the week for any date in history. Each spell starts with a short explanation and a worked example, then a drill that adapts to you, so every problem is just hard enough.

FROM TIMES TABLES TO MATHEMAGIC Eight ranked realms, 58 spells in one continuous ladder: • Initiate: number bonds, adding through ten, and the times tables with a trick for each • Novice: × 11, squares ending in 5, left-to-right adding and subtracting, × 25 • Apprentice: 2-digit × 1-digit, numbers near 100, the teens • Scribe: the Trachtenberg digit rules for × 3 to × 12, and checking answers by casting out nines and elevens • Alchemist: squaring any 2-digit number, the criss-cross method, factoring • Oracle: dividing in your head, fractions, and the cycle of the sevenths • Sorcerer: 3-digit × 2-digit, cubes, and squares of up to five digits • Mathemagician: the day of the week for any date, cube roots and square roots on demand

Plus two side tracks: Everyday (percentages, tips, discounts, sales tax, the rule of 72) and Estimation.

BUILT TO STICK • Spaced repetition decides when each spell comes back, so you keep what you learn without cramming. • Grades come from your answers and your speed. Nobody self-rates. • Miss one and you see the trick worked step by step on that exact problem. • Rank trials at the end of each realm. Already know your tables? Test out and skip ahead. • Speed duels: 60 seconds against your own best. • A daily goal, a streak, and streak freezes that forgive a missed day.

PRIVATE AND OFFLINE No account, no ads, no tracking. Everything stays on your iPhone and works without a connection.

ARCANA PRO Initiate and Novice, the first three Everyday spells, and reviews and duels for everything you've learned are free, for good. Arcana Pro opens the other six realms, every rank trial and both side tracks. Family Sharing is included.

• Yearly: $24.99 a year, with a 7-day free trial for new subscribers • Lifetime: $49.99, once

Prices are in US dollars and vary by country. Payment is charged to your Apple Account at confirmation of purchase, or when the free trial ends. The subscription renews automatically unless it is cancelled at least 24 hours before the end of the current period, and your account is charged for renewal within 24 hours before the end of the period. Manage or cancel it any time in your Apple Account settings.

Terms of Use: https://almasappsllc.github.io/arcana-terms.html Privacy Policy: https://almasappsllc.github.io/arcana-privacy.html

Discovery signals