calculation vs sums

calculation

noun
  • Reckoning, estimate. 

  • The result of calculating. 

  • The act or process of calculating. 

  • An expectation based on circumstances. 

  • The act or process of imagining sequences of potential moves and responses without actually moving the pieces. 

sums

How often have the words calculation and sums occurred in a corpus of books? (source: Google Ngram Viewer )