Teach Factors and Multiples of 3 and 9
Multiples of 3 can be found by adding the individual digits: if the sum of the digits is a multiple of 3, so is the original number. Similarly, the sum of the digits of any multiple of 9 is a multiple of 9. For example:
456 is a multiple of 3, since 4 + 5 + 6 = 15
50022 is a multiple of both 3 and 9, since 5 + 0 + 0 + 2 + 2 = 9
There is an error right near the end of the video; I guess I was trying to talk and think too fast. My apologies to anyone upset by this.
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