Lesson Two Flashcards
Divisible
A number is divisible by a second number if the number can be divided by the second number with a remainder of 0.
Divisibility Tests for 2
The ones digit is 0, 2, 4, 6, or 8
Divisibility Tests for 3
The sum of the digits is divisible by 3
Divisibility Tests for 4
The last two digits are divisible by 4
Divisibility Tests for 5
The ones digit is 0 or 5
Divisibility Tests for 9
The sum of the digits is divisible by 9
Divisibility Tests for 10
The ones digit is 0
Factor
An integer that divides another integer with a remainder of 0
Prime Number
Is a whole number greater than 1 with exactly two factors, 1 and the number itself
Composite Number
Is a whole number greater than 1 with more than two factors.
Prime Factorization
A composite number written as a product of only prime numbers. There is only one prime factorization for a number, regardless of the order of the factors
Greatest Common Factor (GCF)
The GCF of two or more numbers is the greatest number that is a factor of all of the numbers.
Ex: The GCF of 42 and 36
42: 1, 2, 3, 6, 7, 14, 21, 42
36: 1, 2, 3, 4, 6, 9, 12, 18, 36
The factors 1, 2, 3, and 6 are common to both numbers. So the GCF of 42 and 36 is 6.
Rational Number
a number that can be written in the form a/b, where a is an inteer and be is any nonzero integer.
Relatively Prime
two integers, a and b, if 1 is their only common factor. A fraction a/b is in simplest form when a and b are relatively prime.
Terminating Decimal
if the division results in a decimal that stops
Repeating Decimal
if the division results in a decimal that repeats the same digit or group of digits forever.
Least Common Multiple
The LCM of two or more numbers is the least multiple that is common to all of the numbers.
Least Common Denominator
The LCM of the denominators is the least multiple that is common to all of the denominators.
Reciprocals
Two numbers with a product of 1. The reciprocal of a/b is b/a, where a does not equal 0 and b does not equal 0.
Multiplicative Inverse
Another name for the reciprocal of a number.
Exponent
tells how many times a number, or BASE, is used as a factor
Power
An expression using a base and an exponent.
Scientific Notation
Useful for representing and working with very large or very small numbers. A number is in scientific notation if the first factor is greater than or equal to 1 and less than 10 and second factor is a power of 10.
Multiplying a number by 10 raised to n power, when n is positive, moves the decimal point n places to the right.
Multiplying a number by 10 raised to n power, when n is negative, moves the decimal point n places to the left.
