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27 terms

Math 8 Unit 1-The Number System

STUDY
PLAY
WHOLE NUMBER
The Numbers from 0 to +α
NATURAL NUMBER
The Numbers 1 to +α

Also known as Counting Numbers
INTEGER
The set of whole numbers and their opposites
From -α to +α
RATIONAL NUMBER
A number that can be written as a/b where a and b are integers, but b is not equal to 0. .25=¼
IRRATIONAL NUMBER
A number whose decimal form is non-terminating and non-repeating. Cannot be written in the form a/b, where a and b are integers (b cannot be zero).
REAL NUMBER
The set of all rational and irrational numbers.
DECIMAL
A number that is written using the base-ten place value system. 5.6
DECIMAL EXPANSION
Representing a number in decimal form.
¾=.75
REPEATING DECIMAL
A number whose decimal representation eventually repeats the same sequence of digits. 1/3=.3333333...
NON-TERMINATING DECIMAL
A decimal numeral that does not end in an infinite sequence of zeros. 1.42345426343517189191........
TERMINATING DECIMAL
Has a decimal expansion that ends in zero. 0.726500000 = 0.7265
RATIO
A comparison of two quantities by division.
½ or 1 to 2 or 1:2
APPROXIMATION
A result that is not necessarily exact, but is within the limits of accuracy required for a given purpose.
146 ≈ 150 2.57≈3
GREATER THAN
When a number is larger than the other number.
65 > 56
LESS THAN
When a number is smaller than the other number. 107 < 215
RADICAL
The symbol √ which is used to respresent the square root
SQUARE ROOT
A number that when multiplied by itself, equals the given number.
CUBE ROOT
A number that when multiplied by itself, and then mulitplied by itself again equals the given number.
CUBED
A number cubed is the number raised to the third power.
PERFECT SQUARE
A number with integers as its square roots.
1,4,9,16,25....
PERFECT CUBE
A number that can be written as the cube of an integer. 1,8,27,64....
PYTHAGOREAN THEOREM
In any right triangle, the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse, a²+b²=c²
CONVERSE
If the square of one side of a triangle is equal to the sum of the squares of the other two sides, then the triangle is a right triangle.
PROOF
a²+b²=c² where c is the hypotenuse while a and b are the legs of the triangle.
LEGS
The two sides of a right triangle that form the right angle. ( called a and b)
HYPOTENUSE
The side of the right triangle that is opposite the right angle ( called c)
COUNTER EXAMPLE
An example that shows a conjecture is false.