subtract vs sum

subtract

verb
  • To remove or reduce; especially to reduce a quantity or number 

sum

verb
  • To give a summary of. 

  • To add together. 

noun
  • The basic unit of money in Uzbekistan. 

  • The utmost degree. 

  • A summary; the principal points or thoughts when viewed together; the amount; the substance; compendium. 

  • A quantity of money. 

  • The basic unit of money in Kyrgyzstan. 

  • A type of administrative district used in China, Mongolia, and Russia. In Mongolia, a sum is smaller than a province. In China, it is only used in Inner Mongolia, where it is equivalent to a township. 

  • An arithmetic computation, especially one posed to a student as an exercise (not necessarily limited to addition). 

  • A quantity obtained by addition or aggregation. 

  • A central idea or point; gist. 

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