Multiplying by Nine's Trick

I was teaching the classic Multiplying by 9's trick and decided to punch it up a notch. 

My students were in need of a more concrete way to use this trick {many of them kept mixing up the hands, counting fingers in the wrong direction...etc}. 

So we buddied up and wrote on our hands! They were freaking out!






If you are not familiar with the nines trick this is how it works:
I found these great posters:



  1. Number your fingers from left hand pinky to right hand pinky 1-10.
  2. Then take your problem like 9x8.
  3. Starting on the left {pinky labeled 1}, count until you get to the 8th finger {should be right hand middle finger}.
  4. Put that finger under. This is the division between the tens and the ones now.
  5. Count how many are on the left in the tens, and how many are on the right of the down finger and these are the ones. 
  6. In the picture below, there are 7 fingers in all to the left and 2 to the right, therefore the number is 72


 I had some not understanding the role that the "down" finger played so I made this into a "fence". The fingers/numbers could no cross the fence. Then I had them make a T chart on their board to show the tens side and the ones side. Whatever finger they put down had to line up to the T chart and see what finger were in the "Ones Zone" and which were in the "Tens Zone"