Number of elements
A number of elements indicates the size of a set.
Explanation
These numbers can be specified in several ways.
1 Single one, once, simple 2 Double two, twice, couple, duo, both 3 Triple three, 3 times 4 Quadrouple four, 4 times ··· ··· ··· n Multiple several, plural ∞ Infinite countably infinite, uncountably infinite