Chapter 9 Number Properties Flashcards
The integer values that divide evenly into that number.
Factors (or divisors) of an integer
2 is a factor of 12 because 12/2=6, which is an integer
5 is not a factor of 12 because 12/5=2.4 which is not an integer
What can you do to determine the factors of a number?
Create a factor table!
The products that result when that integer is multiplied by another integer.
Multiples of an integer
The multiples of 12 are:
12(1)=12, 12(2)=24, 12(3)=36…
Multiples and factors are essentially what of each Other?
Opposites!
Since 6 is a factor of 24…
24 is a multiple of 6
If an integer is divisible only by 1 and itself, then it is a
Prime number
2, 3, 5, 7, 11, 13, and so on!
1 is not a prime number
2 is the only even prime number
Any factor of an integer that is also prime.
Prime factor
2 and 3 are prime factors of 12, but 4 is not
Two important properties of prime factors:
1) any integer can be expressed as the product of its prime factors
12=223
2) the factors of any integer will be completely determined by the prime factors of that integer
12=223
The factors of 12 are 1, 2, 3, (22), (23), (223)
The largest integer that divides evenly into all the numbers
Break the numbers down into their prime factors and circle the shared factors. The product of the scared factors is your answer
Greatest common factor (GCF)
The smallest integer that is divisible by all the numbers in the set
Must contain the prime factors of each number in the set
Least common multiple (LCM)
Any whole number
Integer
Examples: 2 and -9
3/2 and -7.2 are NOT integers
If “a” is a factor of “b”, and “b” is a factor of “c”, then “a” must be a factor of “c”
If “a” is a factor of “b”, and “b” is a factor of “c”, then “a” must be a factor of “c”
Since 40 is a factor of 240, 8 and 5 (factors of 40) must also be factors of 240
If “y” is divisible by 12, which of the following must be true?
A) “Y” is divisible by 24
B) “Y” is divisible by 6
C) “Y” is divisible by 4
If “y” is divisible by 12 then the prime factors of 12 must be prime factors of “y”.
Create a factor tree.
12=2^2*3
From this we know that “y” has 2,2,&3 in its prime factorization
Since “y” has 2*2 in its prime factorization, y must be divisible by 6
The correct answer is B and C
If you are dividing, is the remainder small or larger than the number you’re dividing by?
X is an integer (quant. Comparison)
- the remainder when x is divided by 4
- 4
4
Because the remainder must always be smaller than the divisor