A number line is a one-dimensional picture in which the integers are shown as specially-marked points evenly spaced on a line. It is often used as an aid in teaching simple addition or subtraction, especially involving negative numbers.

It is divided into two symmetric halves by the origin, i.e. the number zero.

Drawing the number line

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The number line is most often represented as being horizontal. Customarily, positive numbers lie on the right side of zero, and negative numbers lie on the left side of zero. An arrow on either end of the drawing is meant to suggest that the line continues "forever", even though one's paper or chalkboard does not.

See also

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• Real number
• Extended real number line

Elementary mathematics

Zahlengerade | lukusuora ציר המספרים | 数直唶 | 数线