numberness

From number +‎ -ness.

numberness (uncountable)

1. The quality of being a number.
   • Richard Spuler, From Here to There

     […] free-fallers falling less than freely into (predetermined?) places, confirming the grandness of grand, the heaviness of heavy, the truthfulness of lies, the numberness of numbers.

2. (education) Competence in working with numbers and arithmetic; numeracy.
   • 2014, Steve Chinn, The Routledge International Handbook of Dyscalculia and Mathematical Learning Difficulties, page 280:

     Fluent reading and fluency in numberness are analogous.

3. (mathematics) Cardinality.
   • 1966, Saturday Review, volume 49, page 73:

     It helps children to see that the numberness of a "set" can be represented by a numeral.