reckoner
1. [ noun ] (writing) a handbook of tables used to facilitate computation
Synonyms: ready_reckoner
Related terms: handbook
2. [ noun ] an expert at calculation (or at operating calculating machines)
Synonyms: figurer estimator computer calculator
Related terms: expert adder subtracter statistician adder subtracter number_cruncher calculate
Similar spelling:   reasoner
  Regner
  Reisner
  regenerate