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[Ohne Mitleid]

The nines multiplication table trick is kind of a fun thing to have in your repertoire, keeping in mind that it is usually most handy when you are dealing with youth who are just learning the more difficult aspects of math, mainly multiplication and division. You set up your pupil with a particular counting order for their fingers. It is usually easiest to do this with your fingers facing towards you, but either way, the counting order is one to 10 (ten actually ends up being zero, as you will see in practice) from left to right. Pick a number from one to 9 as the multiplier then count off that many fingers from the left to right. When you have arrived at your number, keep that finger held down. The number of fingers to the left of the held down finger will be the digit for the 10s spot and the number of fingers to the right of the held down finger will be the digit for the 1s or single digit spot. In the diagram attached, the example was for 3 times 9 which, if applying the rules above, automatically yields 27. I thought it was pretty cool, but cool would be a normal response from a geekwad and I am just a freakpod. At least they rhyme.

Things still work when you get to the tenth finger, which represents zero, which can be considered "special". Zero counts as zero, so the fingers to the left of it are 9 for the 10s place and 0 for the single digit yielding 90 (9 x 10). I usually try to further the whole process by taking it one more step. The next round beyond the one through ten phase is for 11 through 20, which is the result of the nines (1-10) finger trick plus 90. This incorporates addition and multiplication which usually deepens the understanding to the pupil that multiplication is really just the memorization of addition set results strung together.

Anyway, Have fun
Ohne