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:
“The basis of successful relief in national distress is to mobilize and organize the infinite number of agencies of self help in the community. That has been the American way.”
—Herbert Hoover (1874–1964)
“When all this is over, you know what I’m going to do? I’m gonna get married, gonna have about six kids. I’ll line ‘em up against the wall and tell them what it was like here in Burma. If they don’t cry, I’ll beat the hell out of ‘em.”
—Samuel Fuller, U.S. screenwriter, and Milton Sperling. Samuel Fuller. Barney, Merrill’s Marauders (1962)