This is the 922nd most frequent Japanese word.
計算
Calculation.
The word '計算' (keisan) is used here to mean 'arithmetic or mathematical calculations'.
私は計算が得意です。
I am good at calculations.
Here, '計算' refers to a specific mathematical computation or the result thereof.
その計算は間違っています。
That calculation is incorrect.
In this sentence, '計算' is metaphorically used to describe someone as being strategic or self-serving in their actions.