Sharpness Score Challenges Features Pricing About Download ↓

How Sharp Is Your Mind Today?

Other apps train your brain. MentalMather measures it. Get a daily Sharpness Score based on your speed, accuracy, and personal baseline.

Download on theApp Store
GET IT ONGoogle Play
Try a Problem
0
Sharpness Score
Above your baseline
Sharpness Score

Your brain has RAM and a clock speed. This measures both.

The Sharpness Score compares your daily cognitive performance against your own personal baseline. Not a game score. Not a ranking. A measurement of how sharp you are right now.

⚡
Mental Acuity

Processing speed

How fast you retrieve math facts and execute procedures. Like your CPU clock speed — it tells you how quickly your brain is running today.

🧠
Working Memory

Holding power

Your ability to hold intermediate results while computing the next step. Like RAM — when it's low, you drop numbers mid-calculation.

Why this matters: These two systems compensate for each other. When your processing speed is high, you need less working memory because you finish calculations before numbers fade. The Sharpness Score captures the combined throughput — your total cognitive bandwidth for that day.
The Core Idea

A score that compares you to yourself.

Everyone's brain works differently. What matters is whether your brain is firing at your normal level today. A personal baseline gives you something no ranking can — a daily read on your own cognitive state.

MentalMather Sharpness Score card showing +5.2% above baseline
OperationScore
➕ Addition+24.6%
➖ Subtraction+2.2%
✖️ Multiplication−0.3%
➗ Division+16.1%
Overall Sharpness Score+10.7%
Addition was +24.6% but multiplication was −0.3%. Your brain doesn't treat all operations equally, and neither does the Sharpness Score.
Above Baseline
> +2%
Sharper than your norm
At Baseline
±2%
Right at your typical level
Below Baseline
< −2%
Slower than your norm
"We're not claiming this makes you smarter. We're giving you a number that tells you how sharp you are today."
Think of it like HRV for your heart — useful data, real measurement, not a medical diagnosis.
Guided Assessment

Personalized from the first session.

No guesswork. The app finds your ideal difficulty level by testing you across Easy, Medium, Hard, and Expert — then sets your baseline automatically. Takes about 6 minutes.

Assessment gameplay showing Expert level, problem 656 × 18, with progress dots across Easy Medium Hard Expert
Assessment results screen showing Your Level: Expert with average times — Easy 3s, Medium 7s, Hard 13s, Expert 59s

How the assessment works

You solve 4 problems per level — one of each operation, shuffled. The timer counts up, not down. No pressure. Your speed is what matters, not a ticking clock stressing you out.

If a level is too easy (under 30 seconds average), you advance. If it gets too hard (over 60 seconds), the algorithm finds your sweet spot — the level where you're challenged but not overwhelmed.

At the end, one tap sets your recommended level as your baseline. You're ready for your first Sharpness Test.

📐

Scientific calibration

Not a settings dropdown. The assessment measures your actual performance across all four operations and difficulty levels.

🎯

4 operations × 4 levels

Addition, subtraction, multiplication, and division — tested across Easy through Expert. 16 problems total.

⏱️

~6 minutes to baseline

Quick calibration, then straight into daily sharpness tracking. Your score is trustworthy from day one.

Challenge Mode

Play with anyone.

Parent and child playing MentalMather together on their phones

Challenge your kids to the same problems you're solving. Play with friends in real time. The time handicap makes it a fair fight regardless of skill level — a 10-year-old can genuinely compete against a parent.

Same problems. Same seed. Same order. The only variable is you.

Player A
47 + 83
156 − 89
24 × 7
144 ÷ 12
⚔️
Player B
47 + 83
156 − 89
24 × 7
144 ÷ 12

Time handicap makes it fair.

The creator picks a time and a handicap multiplier. Their opponent gets extra time — same problems, different clocks.

You (creator)2:00
Your opponent6:00 3×
None
1.5×
2×
3×

No account needed

Neither player needs to sign up. Open the app, enter a code, play.

Play on your own time

Create now, your opponent plays whenever. Results compared automatically.

QR or code

Scan to join instantly, or share a short code like MATH-7X4K.

Live Challenges
Think you can beat us?
We post open challenges regularly. Accept one, play it in the app, and see where you rank on the leaderboard. Screen recording required for prize eligibility.
View Open Challenges →
Features

Built for people who want to measure, not just play.

📊

Daily Sharpness Score

A cognitive metric built from your speed and accuracy across all four operations, compared against your personal baseline. Not a game score — a measurement.

🎯

All Four Operations

Addition, subtraction, multiplication, and division. Each tracked independently with separate baselines. Your brain handles each differently, and the score respects that.

📈

Deep Statistics

Track performance over time by operation, difficulty, and date. Personal bests, sloppiness tracking, and session history — real data, not badges.

⚙️

Fully Customizable

Quick Play with your choice of difficulty, time limit, and operations. Timed mode or problem count. Settings persist between sessions.

Try It Now

Think you're fast?

Solve this as fast as you can. In the app, your speed becomes your Sharpness Score.

—
Ready when you are
Pricing

Everything that matters is free.

All core features — Sharpness Score, challenges, statistics, all game modes — are free forever. Premium just removes ads.

Free
$0
  • Sharpness Score
  • All four operations
  • Challenge friends
  • Full statistics & history
  • Unlimited games
  • Ad-free experience
Download on theApp Store
GET IT ONGoogle Play
Premium
$3 / year
  • Sharpness Score
  • All four operations
  • Challenge friends
  • Full statistics & history
  • Unlimited games
  • No advertisements
No auto-renewal. We hate that. Pay once per year, and only if you want to again.
Coming Soon

Common questions

The app builds a personal baseline from your recent solve times across all four operations. Each day you take a standardized 20-problem test, and your speed is compared to your own baseline. Positive means you're sharper than usual. Negative means slower. The score uses outlier filtering and statistical methods so one bad morning doesn't throw off your baseline.
Yes. The baseline uses your recent performance (last 30 days by default), so it naturally shifts as you get faster. A score of +5% always means "5% better than your recent norm." The bar rises with you.
You solve 4 problems per difficulty level, starting at Easy and working up through Expert. The timer counts up — no pressure. If your average solve time stays under 60 seconds, you advance. The algorithm finds the sweet spot where you're challenged but not overwhelmed, then recommends that as your baseline difficulty.
Create a challenge, pick your settings, and share the code or QR. Your opponent gets the exact same problems from a shared seed. Both play on your own time — results are compared once both finish. The time handicap lets a novice genuinely compete against someone experienced.
No catch. All core features are free and always will be. The free tier shows interstitial ads between screens — never during gameplay. Premium ($3/year, no auto-renewal) simply removes those ads. You're paying for a cleaner experience, not a better one.
That's exactly the kind of experiment the Sharpness Score enables. Establish your baseline, start your stack, track your daily score over weeks. You'll see whether your cognitive performance actually changes — with data, not placebo.
No. We hate auto-renewal. You pay $3 once, you get a year of ad-free. When it expires, you decide if you want to pay again. No surprise charges, no cancellation hoops.
Get Started

Ready to find out how sharp you really are?

Download MentalMather for free. No account required. Your Sharpness Score is waiting.

Download on theApp Store
GET IT ONGoogle Play