How to play · 3 min read
Flash Anzan for Beginners: How to Practise Speed Addition
Learn Flash Anzan with a worked number sequence, HumanCalc's actual level settings and a simple way to practise adding numbers as they appear.
A little practice. A sharper game.
Free brain training.Train your mind.
Reaction test: 5 taps, about 30 seconds, no signup. Or choose a game
Daily: 10 mental math questions · about a minute
N = 3
Working memory7 + 5Mental math
Last week's podium
Today's challenge
10 questions. About a minute. Same for everyone.
Worth up to 60 XP today. Streaks multiply XP; freezes save a missed day.
Choose your workout
Start with memory or mental math. Build from there.
Working memory
Dual N-Back
Track a square and a sound at the same time.
PlayMental math
Flash Anzan
Numbers flash. You add them. That's it.
PlayMental math
Mental Arithmetic
Multi-step problems, nothing but your head.
PlayWorking memory
Serial Addition
Add each number to the one before it — not the total.
PlayReflex
Reaction Time
Wait for green. Tap. See your milliseconds.
PlayMental math
Math Chain
Follow a chain of operations. Type the result.
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Mental math
Missing Operator
12 ? 4 = 3. Which operator fits?
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Reflex
Stroop Test
Name the ink color, ignore the word.
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Working memory
Flash Recall
Remember the direction. Rebuild the sequence.
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Reflex
Time Sense
Two beeps. How much time passed?
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Mental math
Blink and Add
Numbers blink. Add, subtract, multiply or divide.
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Missions
Every game and Daily moves you forward, and moves everyone forward.
Your journey
Where will the fox get to?
Your XP moves the fox along ten stops, from Curious Kit to Legendary Fox.
- Curious Kit
- Abacus Adept · 1,000 XP
- Legendary Fox
Community mission
500 runs together this week
—/ 500
Every finished game and Daily counts, signed in or not. Resets Monday 00:00 UTC.
Add a run nowCompetitive Beta
Find a match A different kind of practice.
Flash Anzan. One opponent. A shared clock.
From the blog
All articlesPractice · 3 min read
A Five-Minute Mental Math Practice Routine
Try a short mental math routine with worked addition and multiplication examples, a timed HumanCalc round and a simple accuracy check.
How to play · 3 min read
Dual N-Back Explained: Position and Sound Matches
Understand Dual N-Back with a turn-by-turn N=2 example, Position and Sound controls, common matching mistakes and HumanCalc's progression rule.
Three steps. Five minutes. Daily.
Pick a game
Choose working memory, mental math or reflex. Start with Dual N-Back if you are not sure.
Train at your edge
Difficulty moves with you. The game sits just past comfortable, which is where the work actually happens.
Watch the number move
Keep track of your best scores. Sign in to save your results across devices and see your history.
Why this is built the way it is
01
Research, made practical
Practice inspired by cognitive research, including dual n-back, Stroop and paced serial addition. Each game explains its background and what your score measures.
02
Difficulty that adapts
Training works near the edge of what you can do. Levels move up when you clear them and back down when you don't, so the challenge stays calibrated instead of drifting into boring or impossible.
03
Short, daily, repeatable
Make a little room for focused practice. Play a quick round or stay for a few levels, at a pace that fits your day.
04
Honest about the evidence
Training reliably improves the trained task. Whether that transfers to general intelligence is still argued over. Each game page cites what it is based on so you can judge for yourself.
Questions people actually ask
Does brain training actually work?
It reliably makes you better at the task you train. Broader transfer — to intelligence, memory in daily life, work performance — is genuinely contested, with strong studies on both sides. We cite the source behind each game rather than promising outcomes.
How long until I see results?
There is no fixed timeline. Compare your accuracy and scores across repeated sessions, rather than judging one attempt. Getting better at a game does not by itself demonstrate broader cognitive improvement.
Is HumanCalc free?
Yes, every game is free to play. No subscription, no trial, no paywalled levels. Optional coin packs only buy cosmetics and streak recovery, and never add XP or change a ranking.
Do I need an account?
Dual N-Back, Flash Anzan, Mental Arithmetic, Serial Addition and Reaction Time are open to everyone. Sign in to unlock Math Chain, Missing Operator, Stroop Test, Flash Recall and Time Sense, and save progress across devices. All games are free.
How often does the leaderboard reset?
Every Monday at 00:00 UTC. A seven-day season rewards consistent training without becoming a permanent grind.
Pick a game and start.
Start with a guest game or sign in to unlock the full collection. Every game is free to play, with no download or subscription.
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