Math & school
Calculators for homework and school that show the working, not just the answer.
GPA Calculator
Calculate your GPA on the 4.0 scale from letter grades and credits. Supports weighted GPA…
LCM & GCF Calculator
Find the least common multiple and the greatest common factor of up to 10 numbers, with…
Slope Calculator
Enter two points to get the slope, the equation of the line, both intercepts, the angle…
Standard Deviation Calculator
Paste a list of numbers to get the standard deviation, variance, mean, median, mode…
Scientific Notation Converter
Turn any number into scientific notation, E notation or engineering notation — or turn…
Square Root Calculator
Find the square root, cube root or a higher root of any number, check whether it is a…
Prime Number Checker
Type any whole number to see at once whether it is prime. If it is not, you get its prime…
Quadratic Equation Solver
Enter a, b and c to solve ax² + bx + c = 0. You get the roots — real or complex — the…
Significant Figures Calculator
Find out how many significant figures a number has and round it to any number of sig…
Probability Calculator
Combine the probabilities of two independent events, or find the chance of at least one…
Scientific Calculator
A full scientific calculator in your browser: trigonometry in degrees or radians…
Exponent Calculator
Raise any number to any power, see huge results with every digit, and understand negative…
Guides
How to Write Scientific Notation: Easy Guide
Learn how to write scientific notation step by step — convert huge and tiny numbers with worked examples, clear rules, and a free…
November 6, 2026How to Check If a Number Is Prime: Easy Hand Method
Learn how to check if a number is prime by hand with trial division, smart shortcuts, and worked examples — plus a free instant…
November 3, 2026Slope Formula Explained With Examples: Rise Over Run
Learn the slope formula explained with examples: rise over run, worked calculations, slope types, and real uses on roads and…
October 31, 2026Significant Figures Rules Examples: A Clear Guide
Learn significant figures rules examples with clear rules, zeros explained, and worked rounding examples for homework and lab…
October 28, 2026How to Calculate Probability Basics: Formulas & Examples
Learn how to calculate probability basics with one formula, worked coin-flip and dice examples, and the "and" vs. "or" rules —…
October 24, 2026How to Solve Quadratic Equations: Formula & Examples
Learn how to solve quadratic equations step by step: the quadratic formula, factoring shortcuts, the discriminant, and fully…
October 21, 2026Standard Deviation Explained Simply (2026 Guide)
Standard deviation explained simply: what it measures, population vs. sample formulas, and a step-by-step worked example with…
October 18, 2026How to Calculate GPA 4.0 Scale: Step-by-Step Guide
What is 70% in GPA? It maps to a C grade on most 4.0 scales — see the full percentage-to-GPA table, weighted vs unweighted, with…
October 15, 2026