noun, noun or participle which takes 'suru'
simple calculation; straightforward arithmetic
Refers to a calculation that is uncomplicated, often basic arithmetic. Can also imply a naive or overly simplistic estimate when used figuratively.
この問題は単純計算で解けます。
You can solve this problem with a simple calculation.
単純計算すると、一か月
A simple calculation shows that monthly expenses come to about 100,000 yen.