In basic mathematics, a number line is a picture of a straight line on which every point is assumed to correspond to a real number and every real number to a point. Often the integers are shown as specially-marked points evenly spaced on the line. Although this image only shows the integers from −9 to 9, the line includes all real numbers, continuing forever in each direction, and also numbers not marked that are between the integers. It is often used as an aid in teaching simple addition and subtraction, especially involving negative numbers.
It is divided into two symmetric halves by the origin, i.e. the number zero.
In advanced mathematics, the expressions real number line, or real line are typically used to indicate the above-mentioned concept that every point on a straight line corresponds to a single real number, and vice versa.
Read more about Number Line: Drawing The Number Line
Famous quotes containing the words number and/or line:
“He is the richest man who knows how to draw a benefit from the labors of the greatest number of men, of men in distant countries, and in past times.”
—Ralph Waldo Emerson (1803–1882)
“I fear I agree with your friend in not liking all sermons. Some of them, one has to confess, are rubbish: but then I release my attention from the preacher, and go ahead in any line of thought he may have started: and his after-eloquence acts as a kind of accompaniment—like music while one is reading poetry, which often, to me, adds to the effect.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)