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:
“After mature deliberation of counsel, the good Queen to establish a rule and imitable example unto all posterity, for the moderation and required modesty in a lawful marriage, ordained the number of six times a day as a lawful, necessary and competent limit.”
—Michel de Montaigne (1533–1592)
“Next to the originator of a good sentence is the first quoter of it. Many will read the book before one thinks of quoting a passage. As soon as he has done this, that line will be quoted east and west.”
—Ralph Waldo Emerson (1803–1882)