197
IMPORTANT SYMBOLS,
TERMINOLOGY, FORMULAS,
AND GENERAL MATHEMATICAL
INFORMATION
Common Math Symbols and Terms
Symbol References:
= is equal to
≠ is not equal to
> is greater than
< is less than
≥ is greater than or equal to
≤ is less than or equal to
is parallel to
=
is perpendicular to
Natural numbers — the counting numbers: 1, 2, 3, . . .
Whole numbers — the counting numbers beginning with zero: 0, 1, 2, 3, . . .
Integers — positive and negative whole numbers and zero: . . . −3, −2, −1, 0, 1, 2, . . .
Odd numbers — numbers not divisible by 2: 1, 3, 5, 7, . . .
Even numbers — numbers divisible by 2: 0, 2, 4, 6, . . .
Prime number — number divisible by only 1 and itself: 2, 3, 5, 7, 11, 13, . . .
Composite number — number divisible by more than just 1 and itself: 4, 6, 8, 9,
10, 12, 14, 15, . . .
Squares — the result when numbers are multiplied by themselves, (2
⋅
2 = 4)
(3
⋅
3 = 9): 1, 4, 9,16, 25, 36, . . .
Cubes — the result when numbers are multiplied by themselves twice,

Area = bh or lw
Parallelogram Perimeter = 2(l + w), or 2l + 2w
Area = bh
Trapezoid Perimeter = b
1
+ b
2
+ s
1
+ s
2
,hb b h
bb
area or
2
1
2
12
12
=+
+
^
c
h
m
Circle Circumference = 2πr, or πd
Area =πr
2
Cube Volume = s
⋅

100
= .01 = 1%
1
⁄
10
= .1 = 10%
1
⁄
5
=
2
⁄
10
= .2 = .20 = 20%
3
⁄
10
= .3 = .30 = 30%
2
⁄
5
=
4
⁄
10
= .4 = .40 = 40%
1
⁄
2
=

4
=
25
⁄
100
= .25 = 25%
3
⁄
4
=
75
⁄
100
= .75 = 75%
1
⁄
3
= .33
1
⁄
3
= 33
1
⁄
3
%
2
⁄
3
= .66

2
%
5
⁄
8
= .625 = .62
1
⁄
2
= 62
1
⁄
2
%
7
⁄
8
= .875 = .87
1
⁄
2
= 87
1
⁄
2
%
1
⁄
6
= .16

12 inches (in) = 1 foot (ft)
3 feet = 1 yard (yd)
36 inches = 1 yard
1760 yards = 1 mile (mi)
5280 feet = 1 mile
Area
144 square inches (sq in) = 1 square foot (sq ft)
9 square feet = 1 square yard (sq yd)
Team-LRN
Weight
16 ounces (oz) = 1 pound (lb)
2000 pounds = 1 ton (T)
Capacity
2 cups = 1 pint (pt)
2 pints = 1 quart (qt)
4 quarts = 1 gallon (gal)
4 pecks = 1 bushel
Time
365 days = 1 year
52 weeks = 1 year
10 years = 1 decade
100 years = 1 century
Metric System, or The International
System of Units
Length — meter
Kilometer (km) = 1000 meters (m)
Hectometer (hm) = 100 meters
Dekameter (dam) = 10 meters
10 decimeters (dm) = 1 meter
100 centimeters (cm) = 1 meter

Obtuse angle — Greater than 90 degrees
Acute angle — Less than 90 degrees
Straight angle, or line — Measures 180 degrees
Angle bisector — Divides an angle into two equal angles
Supplementary angles — Two angles whose total is 180 degrees
Complementary angles — Two angles whose total is 90 degrees
Team-LRN