computing vs summation

computing

noun
  • The process or act of calculation. 

  • The study of computers and computer programming. 

  • The use of a computer or computers. 

summation

noun
  • summarization; summary; summing up. 

  • summing; summing up; adding (adding up) of a series of items. 

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