Calculators


 * abacus
 * adding machine
 * arithmograph
 * arithmometer
 * calculating machine
 * cash register
 * compass
 * computer
 * counter
 * difference engine
 * electromechanical calculator
 * handheld calculator or hand calculator
 * isograph
 * mechanical calculator
 * Napier's bones or rods
 * number-cruncher
 * online calculator
 * pocket calculator
 * programmable calculator
 * quipu or khipu
 * rule
 * scientific calculator
 * slide rule or sliding scale
 * suan pan
 * tabulator
 * tally or tally stick
 * totalizator
 * Turing machine