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Factor Rainbows “I can find all the factors of a whole number.” What is a factor? Factoring means to take a number apart. Factors are what you multiply together to get a number. Example: If our number is 10, two factors are 2 and 5 because 2 x 5 is 10. What are Factor Pairs? Factor pairs are two numbers that when Multiplied together equal your target number. For example: Factor pairs for 10 are... 1 x 10 and 2x5 There are 2 factor pairs for the number ten. Finding Factors In order to find all of the factors of a number you need to go through all of the numbers that can be multiplied together to make that number. Our example number 10 has 4 factors... 1, 2, 5 and 10 because... 1 x 10 = 10 2 x 5 = 10 It has 4 factors! Factor Rainbows What is a factor rainbow? A factor rainbow helps you find all of the factors. It is called a rainbow because all of the factor pairs connect to make a rainbow! How do we do it!?!?!? Making a factor rainbow is easy as pie! Let’s try one: Find all of the factors for the number 12. We start by counting and seeing if a number can be multiplied to equal 12. How many factor pairs are there for the number 12? 1 2 3 4 6 12 3 Steps: Step One: Start with 1 and the number itself. Step Two: Count up by ones to see if you can multiply two numbers together to get your target number. Step Three: Stop when you can’t get anymore numbers in between. Step Four: Connect the factor pairs! One more time... How many factor pairs are there for the number 18? How many factor pairs are there for 18? 3 1 2 3 6 9 18 YOU TRY! Make factor rainbows for the following numbers and tell how many factor pairs each number has. 15 24 20 63 35 17