Currency converter for learning exchange-rate maths
Explore exchange ratios between currencies, follow multiplication and reverse conversion, and optionally load a dated daily reference rate.
Open calculatorMaths & numbers
Everyday percentages, sequences and the numbers in between.
Showing 145–168 of 193 tools
Three-set Venn diagram generator
Partition three lists into seven disjoint membership regions with an SVG diagram, counts and a complete member table.
Open calculatorPercentage calculator
Find a percentage of an amount in one step.
Open calculatorPercentage change calculator
Measure an increase or decrease from an original value.
Open calculatorWhat percent calculator
Find what percentage one number is of another.
Open calculatorReverse percentage calculator
Recover the original value before a percentage increase or decrease.
Open calculatorPower calculator
Raise a number to a selected exponent.
Open calculatorSquare root calculator
Find the non-negative square root of a number.
Open calculatorCube root calculator
Find the real cube root of a positive or negative number.
Open calculatorLogarithm calculator
Find the exponent needed to reach a number from a base.
Open calculatorFactorial calculator
Multiply a whole number by all positive integers below it.
Open calculatorGreatest common divisor calculator
Find the largest positive integer that divides both numbers.
Open calculatorLeast common multiple calculator
Find the smallest non-negative common multiple of two integers.
Open calculatorArithmetic sequence calculator
Find the nth term and sum of a sequence with a fixed difference.
Open calculatorGeometric sequence calculator
Find the nth term and sum when each term multiplies by a fixed ratio.
Open calculatorAttendance target calculator
Find a consecutive attended-class requirement and a current absence allowance from an entered threshold.
Open calculatorFinal exam target calculator
Solve the final-score requirement from a normalized current grade, final weight and target course percentage.
Open calculatorMulti-part ratio simplifier and sharing calculator
Simplify two to twenty nonnegative ratio terms and distribute a supplied quantity into exact proportional shares.
Open calculatorCoordinate point set calculator and plotter
Plot unjoined Cartesian points, identify quadrants and axes, and calculate exact mean coordinates, reflections and bounding extents.
Open calculatorPolynomial Riemann sums calculator
Compare left, right and midpoint rectangle sums with an exact polynomial integral and an SVG explanation.
Open calculatorPrime factorization and divisors calculator
Find exact prime powers, the count of positive divisors and their sum in one worked breakdown.
Open calculatorModular exponentiation calculator
Compute a large exponent modulo a whole number using repeated squaring and inspect each selected power.
Open calculatorLinear congruence solver
Solve a·x ≡ b modulo m, including cases with multiple residues or no solution.
Open calculatorChinese remainder theorem calculator
Combine two congruences with coprime moduli into one exact residue class.
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