Large Math Drill - Mental Math
For interview, case. Be smart
Free · In-App Purchases · Designed for iPad. Not verified for macOS.
Train Your Brain to Think in Billions.
■ Can your mental math keep up with high-stakes business?
Most people freeze when they see numbers like a hundred million or a few trillion—but in boardrooms, pitch decks, and consulting interviews, that's just the starting point. If you can’t quickly estimate and compute large figures on the fly, you’re not just slow—you’re forgettable.
This app gives you the edge: a powerful training ground for mastering the kind of numeric fluency that quietly separates decision-makers from everyone else.
■ What does the app do?
It’s laser-focused:
Choose your unit: Thousand, Million, Billion, Trillion
Customize the number types: powers of 10, multiples of 5
Select operation types: Addition, Division, and more
Tap Start and answer lightning-fast using a calculator-style interface
The questions appear at the top, and your ability to instantly recognize, process, and act on large numbers is tested in real-time.
■ Track your progress, in numbers—not feelings.
Forget vague notions of “I think I’m improving.” This app gives you hard data:
Daily accuracy and time-per-question charts
Mistakes are saved and recycled into focused review drills
Compare historical stats to watch both speed and accuracy evolve
■ Why does it work?
Forces your working memory to confront upper limits
Strengthens mental arithmetic under pressure
Encourages structural thinking even in a multiple-choice format
■ Who is this for?
Aspiring consultants, analysts, and investment bankers
Founders, execs, and anyone making real decisions with real numbers
Students prepping for standardized tests, logic interviews, or competitive math
Lifelong learners training for cognitive performance and sharper thinking
■ Use it for interview prep, case studies, quant drills, and more
"Estimate the future market for a trillion-dollar industry."
"Quickly calculate a rough ROI under time pressure."
If those questions make you hesitate, you're not ready. This app builds the intuition and reflexes to handle such questions without blinking.
It’s a secret weapon for case interviews, mental math assessments, business exams, and anywhere sharp numeric instincts are non-negotiable.
■ Other features
Full English unit support: thousand, million, billion, trillion, quadrillion
Clean, intuitive interface
Customizable sound, color themes, and answer modes
■ Numbers Don’t Lie. Neither Should Your Brain.
This isn’t just a calculator. It’s a mental transformation tool.
People who speak the language of large numbers tend to get more respect, more responsibility, and more results.
So don’t get left behind. Start training today—even one minute a day rewires the way you think.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
The developer, Yuto Inagaki, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Location
- Identifiers
- Usage Data
- Diagnostics
Data Linked to You
The following data may be collected and linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- Yuto Inagaki
- Size
- 18.9 MB
- Category
- Education
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - iPad
Requires iPadOS 16.0 or later. - Mac
Requires macOS 13.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- プレミアム会員 ₪9.90
- Copyright
- © 2025 Yuto Inagaki