Calcometry

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Math & homework

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Student and homework helpers: fraction arithmetic, greatest common factor and least common multiple, mean/median/mode, standard deviation, quadratic formula, slope and intercept, Pythagorean theorem, triangle and circle area, and percentage change. Classroom estimates — verify significant figures and show your work for graded assignments.

10 tools in this section

Add, subtract, multiply, or divide fractions and reduce to lowest terms automatically. Free fraction calculator for homework, baking, and everyday math.

Find the greatest common factor (GCF) and least common multiple (LCM) of two whole numbers using the Euclidean algorithm. Free math homework helper.

Calculate mean, median, and mode from a list of numbers in one step. Paste comma-separated values for quick statistics homework and data summaries.

Calculate sample or population standard deviation and variance from any number list. Choose sample (n−1) or population mode for stats homework.

Solve quadratic equations ax² + bx + c = 0 with the quadratic formula. Shows real roots and discriminant — free calculator for algebra homework.

Find slope and y-intercept of the line through two points using m = (y₂ − y₁)/(x₂ − x₁). Free line equation helper for algebra and graphing homework.

Solve for any missing side of a right triangle with the Pythagorean theorem a² + b² = c². Enter two sides; the calculator finds the third instantly.

Find triangle area from base and height or three side lengths using Heron's formula. Switch modes for geometry homework and construction estimates.

Calculate circle area and circumference from radius or diameter using π. Free geometry calculator for homework, crafts, and quick circular measurements.

Calculate percent increase or decrease between an old and new value. Shows absolute change and percentage — handy for prices, grades, and growth rates.