number line

noun

, Mathematics.

1. a straight line on which there is indicated a one-to-one correspondence between points on the line and the set of real numbers.

number line

noun

1. an infinite line on which points represent the real numbers

Word History and Origins

Origin of number line¹

First recorded in 1955–60

Example Sentences

Since at least the early 1990s, researchers have debated whether these mental number lines, or the tendency to order numerically from left to right, are innate or learned.

From Science News

This set of points will be dense on the actual circle, but would make up an infinitesimal amount of the circle, similar to the set of rational numbers on a real number line.

From FiveThirtyEight

For some students, it might help to use a number line to see the relationship between numbers.

From Washington Post

I’ll tell him the next time we’re struggling with fractions on a number line.

From Nautilus

In work that helped earn him a Fields Medal five years later, he established a density function that guarantees evenly spaced triples — not a density as low as Erdős’, but nevertheless one that approaches zero as you go out along the number line.

From Quanta Magazine