Pronunciation: /ˈru lər ˈpɒs tʃə lɪt/ ?
Manipulative 1: Ruler postulate
The ruler postulate states that:
can be paired with a
- The number associated with a point A on the line is called the
points can be paired with the numbers 0 and 1, defining
the length of a unit.
between any two points A and B is designated AB.
- The distance between two points is taken to be positive. Note that a
can be positive or negative.
- The distance between two points A and B can be
found by taking the
of the difference of their coordinates.
allows mathematicians to define
allow us to graph mathematical models. Notice that this postulate does not define a
unit of measure,
it only tells us that a unit of measure is defined by assigning the values of 0
and 1 to two points. The 'ruler' used may be a metric ruler, an english ruler
or even a clock. As long as a number can be assigned to a point on a dimension,
this postulate applies.
- Richard S. Millman, George D. Parker. Geometry: A Metric Approach with Models, 2nd edition, pg 30. Springer, December 17, 1990.
Cite this article as:
Ruler Postulate. 2010-03-15. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/r/rulerpostulate.html.
2010-03-15: Initial version (McAdams, David.