order of magnitude vs quantity

order of magnitude

noun
  • The class of scale or magnitude of any amount, where each class contains values of a fixed ratio (most often 10) to the class preceding it. For example, something that is 2 orders of magnitude larger is 100 times larger, something that is 3 orders of magnitude larger is 1000 times larger, and something that is 6 orders of magnitude larger is a million times larger, because 10² = 100, 10³ = 1000, and 10⁶ = a million. 

quantity

noun
  • A considerable measure or amount. 

  • Length of sounds. 

  • Indicates that the entire preceding expression is henceforth considered a single object. 

  • A fundamental, generic term used when referring to the measurement (count, amount) of a scalar, vector, number of items or to some other way of denominating the value of a collection or group of items. 

  • A specific measured amount. 

  • An indefinite amount of something. 

  • Property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as number and a reference. 

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