Math tools
A focused collection of math tools that run entirely in your browser. The fraction calculator handles addition, subtraction, multiplication, division, and simplification and shows the step-by-step working so the result can be checked or learned from. The Roman numeral converter translates between Arabic numbers and Roman numerals from 1 to 3,999, with a reference table of subtractive pairs.
The fraction calculator works with whole numbers and exact integer arithmetic, and the Roman numeral converter checks every numeral it reads against the standard form. Both update as you type and give the same results on a phone or a laptop. The tools run in your browser.
Read the complete math tools guide
How to use math tools
- Choose the tool you need from the list above.
- Choose an operation and enter the fraction or fractions it needs, or enter a number or Roman numeral and choose a direction.
- The result appears as you type.
- Open Show step-by-step on the fraction calculator, or the reference table on the Roman numeral converter, to check the working.
How the math tools work
The fraction calculator reads each numerator and denominator as a whole number and does the arithmetic with JavaScript BigInt, so products of large inputs stay exact. Addition and subtraction rewrite both fractions over the least common multiple of the denominators, multiplication multiplies straight across, and division multiplies by the reciprocal. Every result is reduced by the greatest common divisor, found with Euclid's algorithm, and shown with its decimal value.
The Roman numeral converter writes a number by taking the largest of 13 values that fits (M, CM, D, CD, C, XC, L, XL, X, IX, V, IV, I) until nothing is left, so 1994 becomes MCMXCIV. To read a numeral it matches the same symbols from left to right and writes the total back; if that does not reproduce the input, as with IIII, it reports a non-standard numeral and suggests the standard form.
In-browser math tools vs the alternatives
| Approach | Privacy | Cost | Best for |
|---|---|---|---|
| In-browser (this site) | All local | Free | Quick fraction work, Roman numeral lookups, learning the steps |
| Hosted math services | Server-side | Free tier + paid | Symbolic algebra, graphing, multi-step problem walkthroughs |
| Calculator app or paper | All local | Free | Quick arithmetic, no copy-paste needed |
For everyday fraction arithmetic and Roman numeral conversion, the in-browser tools are instant and free. For symbolic algebra, calculus, or step-by-step solutions to complex word problems, a hosted computer-algebra service is still the better pick.
When to use these tools
- Use the fraction calculator for homework, cooking ratios, or carpentry measurements. The step-by-step output makes it useful for learning how the operation works rather than just getting an answer.
- Use the Roman numeral converter for dates on monuments and books, copyright marks (MCMLXIV), and outline numbering. The reference table covers subtractive pairs like IV, IX, XL, XC, CD, and CM.
- For percentage operations, the dedicated percentage calculator covers the three most common operations. For unit conversion math, the unit converter handles length, weight, temperature, speed, and volume.
Frequently asked questions
- Are these math tools free?
- Yes. All tools are completely free to use, with no account, payment or registration.
- Can the fraction calculator handle mixed numbers and decimals?
- Enter a mixed number as an improper fraction: 1 3/4 becomes 7/4. Numerators and denominators must be whole numbers, so a decimal such as 1.5 shows an error; write it as 3/2 instead. Every result is shown in lowest terms with its decimal value.
- Why does the Roman numeral converter stop at 3,999?
- Standard Roman numerals have no letter above M (1,000) and never repeat a letter more than three times in a row, so MMMCMXCIX (3,999) is the largest value. Larger numbers were written with a bar over a letter to multiply it by 1,000, a notation the converter does not cover.
- What math tools are available?
- The collection currently includes a fraction calculator (add, subtract, multiply, divide, and simplify fractions) and a Roman numeral converter (convert between Arabic numbers and Roman numerals).