Math Tools Tools

Solve proportional (rule of three) calculations instantly. Enter three known values to find the missing fourth value in a direct or inverse proportion problem.

Calculate population and sample standard deviation, variance, and mean for any data set. Enter numbers separated by commas for an instant statistical summary.

Find the Greatest Common Divisor (GCD) of two or more integers using the Euclidean algorithm. Useful for simplifying fractions and solving number theory problems.

Calculate the Least Common Multiple (LCM) of two or more integers. Essential for adding fractions with different denominators and scheduling problems.

Generate the Fibonacci sequence up to any number of terms. Displays each term, the running sum, and the golden ratio approximation as the sequence grows.

Check if two ratios form a valid proportion (a/b = c/d). Enter four values and instantly verify proportionality with cross-multiplication proof shown.

Check whether any integer is a prime number. For composite numbers, shows the complete prime factorization. Handles numbers up to billions instantly.

Convert between decimal integers and Roman numerals bidirectionally. Supports numbers from 1 to 3,999 and validates Roman numeral input for correct notation.