489order of operations The order in which
operations must be computed when more
than one operation is involved.
ordered pair A pair of numbers that is used
to locate a point on a grid or coordinate
graph.
origin The point (0, 0) on a coordinate grid
where the x-axis and y-axis intersect.
ounce (oz) A customary unit of weight;
16 oz 1 lb.
outcome The result of a probability
experiment.
P
parallel lines Lines in the same plane that
never intersect.
parallelogram A quadrilateral whose
opposite sides are parallel and congruent.
partial product When multiplying numbers
with two or more digits, the product of a sin-
gle digit in one factor and the other factor.
pentagon A polygon with five sides.
percent (%) The ratio or comparison of a
number to 100.
perimeter The distance around a figure.
period A group of three digits set off by
commas in a whole number.
perpendicular lines Intersecting lines in
the same plane that form four right angles.
plane A flat surface that extends indefinitely
in all directions.
point An exact location in space.
polygon A simple closed flat figure made up
of three or more line segments.
prime factorization The expression of a
composite number as the product of prime
numbers.
prime number A whole number other than
0 or 1 that has exactly two factors, itself
and 1.
probability The chance or likelihood of an
event occurring.protractor The tool used to measure
angles.
pyramid A solid figure that has a polygon
for a base and has triangular faces that
meet at a point. A square pyramid has a
square base.
Q
quadrilateral Any four-sided polygon.
R
radius A line segment with endpoints at the
center of a circle and on the circle.
range The difference between the greatest
and least numbers in a set of data.
ratio The comparison of two numbers,
often expressed as a fraction.
ray The part of a line that starts at an
endpoint and goes on forever in one
direction.
rectangle A parallelogram with four right
angles.
rectangular prism A solid figure with six
rectangular faces.
regrouping Trading one from a place for
ten from the next lower place, or ten from a
place for one from the next higher place.
remainder The number left over after
dividing.
7 R2
3 2 3
21
2 remainder
rhombus A parallelogram with all sides the
same length.
right angle An angle that measures 90.
It forms a square corner.
right triangle A triangle that has one right
angle.
rounding Writing a number to the nearest
ten or ten cents, hundred or dollar, and
so on.8204-6_486-490 1/7/06 5:02 AM Page 489