Prime Numbers
True or False:
A prime number has factors of only 1 and the number itself.
True
The number has an even digit in the ones place.
2
A whole number that divides the given whole number evenly.
Factor
GCF stands for this.
Greatest Common Factor
The largest common factor of two or more numbers.
The smallest positive common multiple of the given numbers.
The Least Common Multiple, or LCM
A number with more factors than 1 and itself.
Composite Number
The sum of the digits is divisible by 3.
3
A number with the given number as one of its factors.
Multiple
If two numbers only share 1 as their GCF, they are called this.
Relatively Prime
True or False:
There is only one way to find the LCM of two numbers.
False! There are 2 methods to finding the LCM.
True or False:
1 is both prime & composite.
False. It only has one factor: 1! It is neither prime nor composite.
The ones digit is 0 or 5.
5
0 is only a factor of this number, no others.
0
Step 1 of finding the GCF of two or more numbers.
For instance, 40 & 100.
Find the prime factorization of each number.
40: (23)(5)
100: (22)(52)
A way of finding the LCM of relatively small numbers, such as 4 and 5.
List the multiples, until they have one that matches.
4: 4, 8, 12, 16, 20
5: 5, 10, 15, 20
All composite numbers can be broken down into their ____ factors.
Prime
The number is divisible by both 2 & 3.
6
A number divided by 0.
Undefined. You cannot divide any number into equal groups of nothing.
Step 2 in finding the GCF of two or more numbers.
For instance, 40 & 100.
Circle only the common factors, ignoring any that are not common, or multiplied more than the smallest number of times.
40: (23) (5)
100: (22) (52)
The first step in finding the LCM of larger numbers, such as 84 & 78.
Find the prime factorization of each number.
42: (22)(3)(7)
78: (2)(3)(13)
The prime factorization of ___ is (3)(22)(5)
60
Looking at the last 3 digits, you can tell if a number is divisible by ___.
8
When listing multiples of a number, you start with this.
The number itself!
The final step in finding the GCF of multiple numbers.
For instance, 40 & 100.
Multiply the smallest magnitude of the common factors together.
40: (23) (5)
100: (22) (52)
(22)(5)=(4)(5)=20
The second step in finding the LCM of larger numbers, such as 42 & 78.
Multiply the largest power of each different factor together.
42: (22) (3) (7)
78: (2)(3) (13)
(22)(3)(7)(13)=1,092