# PSSA Math Dictionary

Last Updated: 4/3/2019 8:38 PM

PSSA Dictionary!

Angle - the measurement of the space between two straight lines that extend from a common point.  There are several types:  acute, obtuse, right, straight, reflex, opposite, supplementary, complimentary, alternate.

Acute Angle - an angle measuring between 0 and 90 degrees

Algebraic Equations - there are at least 3 possible methods to solve simple algebraic equations. Give all 3 a try!

First Way Look at the algebraic question and mentally fill in the blank;

(2) Secondary Way - whatever you do to one side of the equals, you have to do exactly the same on the other side

n + 7 = 29

n + 7 - 7 = 29 - 7

n = 22

(3) Opposite Way - the goal is to make the "n" lonely, so the + 7 has to be removed, but if you take it away from one side, then you have to do the opposite to the other side

n + 7 = 29

n = 29 - 7

n = 22

Angle Relationships:  (geometry)

- Complimentary Angles - 2 angles that add up to 90 degrees

- Supplementary Angles - 2 angles that add up to 180 degrees

- Opposite Angles - where there are 2 lines that intersect, the opposite angles are equal

- Perpendicular Lines - lines that intersect to form a right angle (90 degrees)

- Parallel Lines - two lines that are on the same plane but do NOT intersect

- Transversal Line - a line or line segment that crosses or intersects two other lines.  If the 2 other lines are parallel, then the alternate angles are equal, the corresponding angles are equal and the co-interior angles add to 180 degrees

Area of a regular shaped Prism - formula: A = L x W

Area of a Triangle -another special formula A = bh

Average -a set of numbers from the sum of specified numbers divided by the number of numbers

Bar Graph - compares similar items by using bars of different heights on a graph

PEDMAS - Order of Operations for calculations in this order:   Parenthsies, Exponents, Division, Multiplication, Addition, Subtraction

Bisect - to divide into two equal parts

Broken-Line Graph - uses a series of line segments to show how something changes with time.

Capacity:  the amount a container can hold when filled

Chord:  a line segment with its endpoints on the circle

Circumference:  the "perimeter" of a circle, the distance around the circle -   C = pd   where p = 3.14

Composite Numbers - a number that has more than 2 factors.  Example:  the factors of 8 are 1, 2, 4, 8, therefore it is NOT a prime number.

Congruent - in geometry, figures and shapes are equal being identical in size and shape

Comparing Symbols - < less than,≤ less than or equal to, > greater than,  ≥ greater than or equal to, = equal to, ≠  not equal to

Compass - used in geometry

Denominator - the bottom number in a fraction

Diameter - (d) a line that goes through the whole circle including the centre

Difference - subtract

Dividend - the number that is to be divided by another

Divisor - the number by which the dividend is to be divided

Expanded Form or Expanded Notation- expanding or extending numerals into an expression.  Example:

4629.35 = (4x1000) + (6x100) + (2x10) + (9x1) + (3x0.1) + (5x0.01)

Estimate - to make a rough calculation which may involve approximating.  This helps to understand to understand big complex numbers 192 x 9 = 200 x 10 = 2000

Exponents - the numerical symbol used to indicate the raising of a base number to a power.

Example:   4©ø = 4x4x4 = 64

Expression - an algebra question or problem

Equation - an algebra statement of equality between two expressions

Evaluate - solve the problem

Edge - a line forming the intersection of two faces of a polyhedron

Factors - all of the numbers which divide exactly into a number.  Example: the factors of 12 are 1, 2, 3, 4, 6 and 12

Factor Tree:  a diagram that shows the prime factors of a composite number

Fractions - part of whole numbers, also related to decimals

¨ý (5 is numerator/8 is denominator)

There are many important rules when working with Fractions:

1. When sorting, adding or subtracting fractions, use common denominators;

2. When multiplying, multiply the numerator separately, then the denominators

3/4 x 1/3 = 3/12

3.  When dividing, multiply the reciprocal:

3/5 divide 2/3 = 3/5 x 3/2 = 9/10

4.  Always reduce fractions at the end of your answer:   3/4 x 1/3 = 3/12 = 1/4

5.  Conversion into decimals is easy!

1/6 is a division statement - 1 divided by 6

6.  Equivalent fractions are 2 fractions that represent the same rational number:

2/4 = 4/8 = 8/16 = 1/2

7.  Improper fractions - when the numerator is larger than the denominator  7/5

8.  Mixed fractions - improper fractions is a mixed number:   7/5 = 1 2/5

Face - flat surface of a polyhedron

Frequence - the number of times an event has occurred

Geometry - in three-dimensional (3D) geometry, the objects have edges and faces

Greatest Common Factor (GCF) - the largest factor that 2 or more numbers have in common

Hypotenuse - in a right triangle, the hypotenuse is the line opposite the right angle.

Heptagon - A polygon with 7 sides

Histogram - a bar graph in which the labes for the bares are in numericical intervals.

Intersecting Lines - lines that intersect

Inequalities - symbols used to compare numbers - < less than, ¡Â less than or equal to, > greater than, ¡Ã greater than or equal to, = equal to, ¡Á not equal to

Integers - positive and negative counting numbers

Integer Line - a line with a middle of 0 and positive numbers on the right side and negative numbers on the left

Integer Rules - multiplying (also same for dividing) -

+ x + = +

- x - =  +

+ x - = -

- x - = -

Isosceles Triangle - a triangle with 2 equal sides

Line Graph:

Line Segment - in geometry, part of a line, written as AB Least common denominator (LCD) - The least common multiple of the donominators in two or more fractions

Least Common Multiple (LCM) - The smallest number other than zero this is a common multiple of two or more numbers.

Leg (Of a Right triangle) - Either of the two sides that form the right anglel in a right triangle

Line plot - a graph showing the frequency of data on a number line.

Mean - same as average

Median - the middle number in a set of numbers arranged in order

Mode - the number that occurs most often in a set of numbers

Metric Conversions:

# Metric Conversions

0.001

0.01

1

1,000

milli

centi

kilo

mm

cm

metre (distance)

km

mg

gram (solids)

kg

mL

Litre (liquids)

kL

Net - a 2D figure that can be folded to make a polyhedron.

Numerals - symbols used to denote numbers.  Example:  1, 2, 3, ......

Numerator - the top number of a fraction

Order of Operations - specific rules that must be followed when solving a math problem (such as PEDMAS)

Obtuse Angle - an angle greater than 90 degrees but less than 180 degrees

Of - in math terms, it means "to multiply"

Ordered Pairs - written as (1,2)

Parallel Lines - lines that never intersect

Plane - a flat surface that extends infinitely in all directions

Perimeter - the distance around an object measured along a boundary, add up the distances of all of the sides.

Percent - a number calculated out of 100.  It is related to fractions and decimals.  A fraction can be changed into a percent using division (4/5 = 4 divided by 5 = 0.80 x 100 = 80%).  A decimal can be changed into a percent using multiplication (0.33 x 100 - 33 %)

Perpendicular Lines - intersect at right angles

Pi - a Greek symbol representing the number for 3.14

Pictograph - a graph using pictures

Place Value: position of a number determines its value (see chart)

Point - a geometric location on a line or in space

Polyhedron - a solid shape, each of whose face is a polygon

Polygon - in geometry, a plane (2D) shape having 3 or more sides.  Regular polygons have all equal sides and all equal angles.

Powers of Ten Multiply: usually add zeroes but sometimes move the decimal to the left.

32 x 1000 = 32000, 32 x 0.001 = 0.032

Divide: usually move the decimal to the left but sometimes add zeroes (which might also mean move the decimal to the right).

32 ./. 1000 = 0.032, 32 ./. 0.01 = 3200

Prime Number - a number that has only 2 factors, 1 and the number itself.  Examples:  2, 3, 5, 7, 11, 13, 17, 19 ....

Prism - a polyhedron having the same cross section through its length

Product - the answer from a multiplication question

Pyramid - a polyhedron with a polygon for its base (square, triangle) and the other faces are triangles with a common vertex

Pythagorean Theorum - in a right-angled triangle, the area of the square on the hypotenuse is equal to the sum of the areas of the squares on the remaining sides. Formula: Hypotenuse(squared) = [one side(squared)] x [other side (squared)]

Quotient - the answer from division questions

Quadrants - the four regions of a coordiante plane that are separated by the axes.

Radius - the line from the centre to the boundary of the circle

Range - the difference between the greates and the lease numbers in a set of data

Rate - a comparison of two numbers, similar to ratio, but with different units of measurement

Ratio - a comparison of two numbers.  It is used to compare two quantities measured in similar units by comparing

Ray - a straight line extending from a point (the point is the beginning of the ray)

Reflex Angle - an angle that measures more than 180 degrees and less than 360 degrees

Repeating Decimal - a decimal that has a repeating sequence of numbers after the decimal point

0.333.....  or 0.3

Right Angle - equals 90 degrees

Rounding - rules to help understand complicated numbers

5 and over - round up

4 and under - round down

HINT:  look at the number beside it

Sample - instead of doing a large survey, a small survey or sample can be conducted.  100 people might indicate 100,000 people

Scientific Notation - a number that is written using scientific notation is as follows:

Shell - a 3-dimensional object whose interior is empty

Skeleton - a representation of the edges of a 3D object

Square Root - one of two equal factors of a number

Solid - a 3D object whose interior is completely filled

Standard Form - the regular way in which numbers are usually written.

Straight Angle - an angle that measures 180 degrees

Stem and Leaf Plot - a chart that organizes data in increasing order

Symmetry - a figure has line symmetry if a line can separate the figure into two congruent parts.

Triangle - triangles are classified in two possible ways:  by angle or sides

Tally Chart - a survey

Table of Values - a chart to organize variables for graphing

Transformtiation - the moving of a figure by a translation (slide), rotation - (turn) or reflection (flip)

Unit Rate - a comparison of two numbers in which the 2nd number is usually 1.

Example:  Cans of soup are \$0.74 / each

5 cans = \$3.70

But a case of soup = 24 cans x \$0.74/each = \$17.76

(Case is 24 / dozen is 12)

km/h = the number of kms in 1 hour

Vertex / Vertices  - a point where two or more geometric lines meet

Volume  - the measure of the amount of space that a solid figure occupies.  The volume of a prism measures everything INSIDE the figure.

For a regular shaped prism:   V = L x W x H

For a triangle:                       V = Area of Base x H

Whole number - any of the numbers 0, 1,2 ,3,... and so on

X Coordinate:

Y Coordinate:

# Polygons

Formula:   180 ¨¬ x (n-2)

Polygon

Number of Sides:

Sum of Interior Angles:

Triangle

3

180 degrees

4

360 degrees

Pentagon

5

540 degrees

Hexagon

6

720 degrees

Heptagon

7

900 degrees

Octagon

8

1080 degrees

Nonagon

9

1260 degrees

Decagon

10

1440 degrees

Dodecagon

12

1800 degrees

1

2

3

4

5

6

7

8

9

10

11

12

1

1

2

3

4

5

6

7

8

9

10

11

12

2

2

4

6

8

10

12

14

16

18

20

22

24

3

3

6

9

12

15

18

21

24

27

30

33

36

4

4

8

12

16

20

24

28

32

36

40

44

48

5

5

10

15

20

25

30

35

40

45

50

55

60

6

6

12

18

24

30

36

42

48

54

60

66

72

7

7

14

21

28

35

42

49

56

63

70

77

84

8

8

16

24

32

40

48

56

64

72

80

88

96

9

9

18

27

36

45

54

63

72

81

90

99

108

10

10

20

30

40

50

60

70

80

90

100

110

120

11

11

22

33

44

55

66

77

88

99

110

121

132

12

12

24

36

48

60

72

84

96

108

120

132

144