名詞 calculation:

1. the procedure of calculating; determining something by mathematical or logical methods
   同義詞：computation, computing
2. problem solving that involves numbers or quantities
   同義詞：computation, figuring, reckoning
3. planning something carefully and intentionally
   同義詞：deliberation

1. Where (ie At what point) did I go wrong in my calculation?
   我在計算中什麼地方出了差錯?
2. My calculation is based on notional figures, since the actual figures are not yet available.
   因尚無實際數字，我是根據估計的數字計算的。
3. Your calculation is way off beam.
   你的計算大錯特錯。
4. The calculation was difficult, but we finally cracked it.
   計算起來很費勁，然而我們終於解決了。
5. You are out in your calculation.
   你失算了。
6. After much calculation, they offered him the job.
   經過慎重考慮，他們把這項工作交給他了。

cal.cu.la.tion

n.（名詞）
Abbr. calc.
縮寫 calc.
The act, process, or result of calculating.
計算：計算的行為、操作或結果
An estimate based on probabilities.
估計：基于概率的一種估計
Careful, often cunning estimation and planning of likely outcomes, especially to advance one`s own interests.
深思熟慮：認真的、常是機敏的對可能結果的估計和計劃，特指為提高個人的利益

【引伸】
cal.cula.tive
adj.（形容詞）