reckoner

名词 reckoner:

1. an expert at calculation (or at operating calculating machines)
   同义词：calculator, figurer, estimator, computer
2. a handbook of tables used to facilitate computation
   同义词：ready reckoner

reck.on.er

n.（名词）
A handbook of mathematical tables used to facilitate computation.
计算表：用于帮助方便计算的手册或算术表格