Math & Number Tools Hub — Free Online Tool
100% free browser math toolkit—no signup. Percentage patterns, calculator link, Roman numerals, GPA from credits × grades, prime checks, GCD/LCM,…
Frequently asked questions: How do I calculate percentage change between two values? Open /tools/percentage-calculator for relative percent change ((B−A)/A)×100—common for discounts, growth rates, and before/after comparisons. Is there a free prime number checker online? /tools/prime-checker uses trial division for teaching-sized integers—not industrial cryptography, but fast for homework and puzzles. Can I convert Roman numerals in the browser? Yes—/tools/roman-numeral-converter handles classic subtractive notation through MMMCMXCIX in your tab with no signup. Do these tools upload my numbers? No. Arithmetic, conversions, and random generation run entirely in your browser unless a tool explicitly calls an external API (none of the math hub pages do).
Previous in catalog Next in catalog
Frequently asked questions
- How do I calculate percentage change between two values?
- Open /tools/percentage-calculator for relative percent change ((B−A)/A)×100—common for discounts, growth rates, and before/after comparisons.
- Is there a free prime number checker online?
- /tools/prime-checker uses trial division for teaching-sized integers—not industrial cryptography, but fast for homework and puzzles.
- Can I convert Roman numerals in the browser?
- Yes—/tools/roman-numeral-converter handles classic subtractive notation through MMMCMXCIX in your tab with no signup.
- Do these tools upload my numbers?
- No. Arithmetic, conversions, and random generation run entirely in your browser unless a tool explicitly calls an external API (none of the math hub pages do).