reckoner

• Существительное, обозначающее человека, искусного в вычислениях, или справочник, содержащий таблицы для облегчения расчётов.

A noun referring to a person skilled in calculation or a handbook containing tables used to facilitate computation.

1. Expert in calculationC1formal

   A person who is skilled at performing calculations or operating calculating machines.

   Вычислитель

   • The old reckoner could add large sums in his head.
   • She worked as a reckoner for the accounting firm.
   • The team relied on the reckoner for accurate financial projections.

   Synonymsarithmeticiancalculatorcomputercountermathematiciannumber cruncher

2. Reference book for calculationsC1formal

   A handbook or book of tables used to simplify and speed up mathematical computations.

   Справочник для вычислений

   • The carpenter used a ready reckoner to estimate material costs.
   • Before calculators, every office had a reckoner for quick math.
   • The reckoner contained tables for interest, taxes, and conversions.

   Synonymsready reckoner