8 Now you try …Find the prime factorization of:4048
9 GCFThe Greatest Common Factor between at least two numbers… used to simplify fractions.
10 GCFThe greatest common factor of two or more numbers is the greatest factor that is in common to those numbers.The GCF can be found by:Listing all the factors of each number and then finding the largest number in all lists to give the GCF.Do a factor tree of each number and the prime factors that are in all trees multiply to give the GCF.
11 Listing all the factors… This works best when the numbers are small and have few factors.12 and 15Factors of 12: 1, 2, 3, 4, 6, 12Factors of 15: 1, 3, 5, 15GCF= 3
12 Do a factor tree…This works best when the numbers are large and have many factors.These two treesshare a 3 and 5.Multiply thesetwo togetherand get 15.GCF=15
13 Try another with a factor tree 45 and 81GCF=3x3=9
15 LCMLeast Common Multiple between at least two numbers… used to find a common denominator to help add and subtract fractions.
16 MultipleThe multiple of a number is a product of that number and a whole number…Meaning multiply!Multiples of 5:5, 10, 15, 20, 25, 30…Multiples of 3:3, 6, 9, 12, 15, 18, 21…
17 LCMLeast Common Multiple is the smallest multiple of two or more numbers.The easiest way to find the LCM:Start to list all the multiples of the numbers involved and stop as soon as you have a number in common to both lists.Ex: between 3 and 55, 10, 15, 20…3, 6, 9, 12, 15…So the LCM is 15!
18 You try it! Find the LCM between 4 and 9 Make a list of multiples of each number.4, 8, 12, 16, 20, 24, 28, 32, 36, 409, 18, 27, 36..LCM = 36!