Tricks to Help You Learn the Multiplication Fact “9”

The multiplication fact 9 has some patterns that can be used to help master the memorization of its multiples.

*Using a 100 chart shade in all the multiples of 9.  What patterns do you see?

Notice that the sum of the digits of the multiples will equal 9.

9 x 1=9                0 + 9=9

9 x 2=18              1 + 8=9

9 x 3=27              2 + 7=9

9 x 4=36             3 + 6=9

9 x 5=45             4 + 5=9

9 x 6=54             5 + 4=9

9 x 7=63             6 + 3=9

9 x 8=72             7 + 2=9

9 x 9=81             8 + 1=9

9 x 10=90          9 + 0=9

Also notice that the first digit in the product is one less than the factor 9 is being multiplied with.  For example, 9 x 5 will have a product that begins with 4, 9 x 6 will have a product that begins with a 5.  Since you know this pattern and the sum of the digits in the products through 10 equal 9, you can memorize your 9 facts.  The only Math book that I have seen this taught is Saxon Math.

Another method that may be used to remember the nine multiplication facts is to use your fingers.  Turn your palms so they are facing you.  Your thumbs should be facing out.  For 9 x 1, pull your left thumb in to your palm.  Look to the to the left of your thumb, there is no finger.  Look to the right and there are nine fingers-9 x 1=9.  Put your index finger down on your palm.  The thumb is on the left which represents a 1.  There are 8 fingers to the right of your index finger-9 x 2=18.  Put your middle finger down on your palm.  There are 2 fingers to the left and 7 fingers to the right-9 x 3=27.  You can use this helping tool through the multiple of 10.

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