▶ Playable Free
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📝 What it trains
Odd One Out — Sides Count — Visual reasoning challenge: identify which shape doesn't belong with the others. Trains pattern recognition, abstract reasoning and visual attention. Common in IQ tests and cognitive assessments like Raven's Progressive Matrices.
- Processing speed — how fast your brain handles numerical information.
- Working memory — holding partial results while you compute.
- Sustained attention — staying accurate as the timer pressures you.
🎯 How to play
- Press Start Drill — a new problem appears every round.
- Solve in your head — no scratch paper.
- Type the answer and press Enter.
- Correct answers extend your streak; wrong answers cost no time but reset the streak.
- You have 60 seconds. Beat your high score, then share your result.
🧪 The science
Mental arithmetic recruits the parietal cortex (number magnitude), prefrontal cortex (working memory) and the basal ganglia (procedural fluency). Daily 5-minute drills have been shown to improve fluid intelligence scores in adults over 8 weeks.
Bergman-Nutley & Klingberg (2014). Effect of working-memory training on working memory, arithmetic and following instructions. Psychological Research 78(6), 869-877.
💡 Tips & strategy
- Chunk large numbers — 47 + 38 = (40 + 30) + (7 + 8) = 85.
- Round and adjust — 98 × 4 ≈ 100 × 4 − 2 × 4 = 392.
- Memorize squares to 25² — speeds up multiplication and percentages.
- Aim for accuracy first — speed comes naturally with practice.
❓ Frequently asked
Is it really free?
Yes — every exercise on Brain Training is free. No sign-up, no paywall.
How long should I train each day?
Research suggests 5–15 minutes daily produces measurable gains in 4–8 weeks. Consistency beats long sessions.
Does mental math really make you smarter?
It improves processing speed and working memory directly, with modest transfer to fluid reasoning tasks.
Is there a mobile app?
Yes — "Brain Training: Math & Memory" is free on iOS App Store and Google Play.
