11 × 13 = ?
Mental math. No course, no fluff — just practice.
11x13 is a pure practice app: open it and go. Short problems, several answers, one correct. Ten minutes a day make numbers feel natural again.
Free to download — the basic operations stay free forever.
Four packs
Basic operations
Free foreverThe foundation: add, subtract, multiply, divide — from times tables to 11×13 and beyond.
Advanced
Percentages, roots, powers — the math of everyday life, school and work.
Higher
Derivatives and integrals in your head — routine for high school and university.
Geometry
Symbol equations, counting corners, matching shapes — geometry made tangible, entirely without words.
How it works
25% · 80 = ?
Wordless problems
No word problems, no explanations — just the math. That's why 11x13 works equally well in every language.
↗12·B3
Levels & bands
Your level grows with every correct answer. New bands introduce genuinely new kinds of problems — it stays challenging, never repetitive.
★ Score
Visible progress
A level per operation, an overall score, history curves and a practice grid show what you've mastered — with an optional Game Center leaderboard.
∞
Everything — one purchase, no subscription
The “Everything” pack unlocks every operation. Try it free for 14 days, then decide. The basic operations stay free either way.
€2.99 · one-time · shown in your local currency on the App Store · iPhone & iPad · 7 languages