calculator (n.)

• abacus
• accountant
• actuary
• adding
• auditor
• bookkeeper
• clerk
• comptroller
• computation
• computer
• controller
• counter
• estimator
• figurer
• intriguer
• machinator
• maneuverer
• manipulator
• quipu
• reckoner
• recorder
• registrar
• rule
• schemer
• statistician
• strategist
• tabulator
• tactician
• wire-puller