Classroom Calculators
Twenty tools that show their working, grouped by subject.
These run entirely in the page. Nothing is uploaded, nothing is stored, and no sign-up is required. Each one prints the intermediate steps rather than just an answer, because in almost every case the method is what is being assessed.
By subject
Percentages and ratiosRatio, percent change, percent difference, fraction to percent
FractionsDecimal to fraction, fraction to decimal, improper fractions
Algebra and numberGCF and LCM, quadratic formula, regression, limits
StatisticsStandard deviation, binomial, normal and Poisson
ChemistryMolar mass, density, dilution, worked compounds
GradesFinal exam score needed, weighted and unweighted GPA
Logic and number bases
Boolean algebra calculatorTruth table, minterms, SOP and POS
Truth table generatorFull table for any logic expression
Number base converterBinary, octal, decimal, hex, with the working
Background reading sits alongside the tools: number systems, statistics, graphs and charts, geometric shapes.