Glossary - Pp

Parallel

Given distinct lines in the plane that are infinite in both directions, the lines are parallel if they never meet. Two distinct lines in the coordinate plane are parallel if and only if they have the same slope.

Parallel Lines

Lines in the same plane that never intersect no matter how far they are extended. They are always equidistant (the same distance) from each other.

Parallelogram

A quadrilateral with two pairs of parallel and congruent sides.

Pattern

A design (geometric) or sequence (numeric or algebraic) that is predictable because some aspect of it repeats. Examples: Numeric pattern that adds 3s:4, 7, 10, 13, ...Algebraic pattern that adds one to the multiple:x, x2, x3,... Spirals in a cactus. Geometric Designs.

Penny

A coin with a value of one cent or 1/100 of a dollar.

Pentagon

A polygon with five sides and five angles.

Percent

A number expressed in relation to 100; represented by the symbol %(e.g., 40 parts out of 100 is 40%).

Percent Decrease

The magnitude of decrease expressed as a percent of the original quantity.

Percent Increase

The magnitude of increase as a percent of the original quantity.

Percentile

A value on a scale that indicates the percent of a distribution that is equal to it or below it. For example, a score at the 95th percentile is equal to or better than 95 percent of the scores.

Perfect Square

A whole number resulting from multiplying an integer by itself; a is a perfect square if a = n*n and n is an integer (e.g. 16=4*4 and 121=(-11)*(-11)).

Perimeter

The distance around a closed figure.

Permutation

A permutation of the set of numbers {1, 2,..., n} is a reordering of these numbers. Possible arrangements of a set of objects in which the order of the arrangement makes a difference. Example: Determine all the different ways five books can be arranged in order on a shelf.

Perpendicular

Two lines, segments, or rays that intersect to form right angles.

Perpendicular Bisector

A line, segment, or ray that is perpendicular to and bisects a line segment.

Personal Reference

Something that a person can refer to as a standard, for the purpose of comparison (e.g., knowing the width of your pinky finger is approximately 1 cm). Examples:The height of the room is about twice as tall as a student. The length of a fifth grader’s arm is about 2 feet.

Phenomena

Something that is observable. Singular Form: Phenomenon.

Physical Model

A physical model is a representation of something using objects.

Physical Phenomena

Problems in the physical world that involve math. Example: Acceleration due to gravity.

Pi

The ratio of the circumference of any circle to its diameter. Pi is an irrational number with an approximate value of22/7 or 3.14159.

Problem Solving Strategies

Various methods used to solve word problems; strategies may include, but are not limited to: acting it out, drawing a picture or graph, using logical reasoning, looking for a pattern, using a process of elimination, creating an organized chart or list, solving a simpler but related problem, using trial and error (guess and check), working backwards, writing an equation.

Product

The answer in a multiplication problem. For example, 6x3=18, 18 is the product of 6x3.

Profit

The amount of money left after expenses have been subtracted from income.

Proof

A valid argument, expressed in written form, justified by axioms, definitions, and theorems.

Proper Fraction

A fraction whose numerator is less than its denominator.

Properties

Characteristics of a shape or object (e.g., size, shape, number of faces, or ability to be stacked or rolled).

Properties of Real Numbers

Rules that apply to the operations with real numbers. Examples: Commutative Property: a + b = b + a or ab=ba, Associative Property: a + (b + c) = (a + b) + c or a(bc) = (ab)c, Distributive Property: a(b + c) = ab + ac, Identity: a + 0 = a or a*1=a, Inverse: a + (–a) = 0

Proportion

An equation which states that two ratios are equivalent (e.g., 5/10=1/2 or 5:10 = 1:2).

Proportional Reasoning

Using the concept of proportions when analyzing and solving a mathematical situation. Example: If triangle ABC is similar to triangle XYZ and AB = 15 when sideXY = 75, find BC when YZ = 150.

Proportionality

The quality, character, or fact of being proportional.

Protractor

An instrument used to find the degree measure of an angle.

Pyramid

A polyhedron whose base is a polygon and whose other faces are triangles that share a common vertex .

Pythagorean Theorem

The mathematical relationship stating that in any right triangle the sum of the squares of the two legs is equal to the square of the hypotenuse (the longest side of the triangle). If a and b are the lengths of the legs and c is the length of the hypotenuse, then a² + b² = c².