Ready to test your business brain?
10 questions · ~10 seconds each · margins, ROI, discounts, break-even and more.
Why practice mental math?
Numeracy is a use-it-or-lose-it skill. Founders and freelancers who can estimate a margin, a discount stack, or a runway number in their head — even roughly — catch bad deals and bad pricing faster than people who reach for a calculator for everything. Quick mental-math games like this one are a light, low-stakes way to keep that muscle warm.
None of these questions require anything beyond arithmetic you already know. If a question stumps you, that's a signal, not a verdict — the related calculators below work through the exact same formulas slowly, with every step shown.
Frequently asked questions
Is this quiz free?
Yes — completely free, no signup, no data stored. Your score only lives in your browser tab.
How is the score calculated?
Each correct answer is worth 10 points. Answer all 10 questions correctly for a 20-point perfect-round bonus. Running out of time on a question counts as a miss.
Does practicing mental math actually help in business?
Yes. Being able to sanity-check a margin, a discount, or a runway estimate in your head — even roughly — helps you catch bad numbers before you act on them. It will not replace a real calculator for anything that matters, but it builds number intuition.
I got a low score — where should I practice for real?
Every question in this quiz is based on a real RateKit calculator. Check the related tools below to work through the actual math slowly, with formulas shown.