Finger Calculator For The Nines

I learned in a school book how to multiply by nine the easy way. It's a trick! What you do is put up all ten fingers. Then give your fingers names - this is the fun part. Start with your thumb and call him "one". Name the others by their number order. Next, you go 9 x 9 = what? You have to tell the number nine finger to duck. Then, you count how many fingers are on the left side of number nine. There are 8. Well how many are on the right? There is 1. So, you got your answer: 81! It's so cool! Multiplication. Another example is this: 9 x 4. Set your hands up. Duck the number four finger. Count the numbers on the left side of your ducked finger. It's 3. Now, count the fingers on the other side of the ducked finger. That is 6. You've discovered that 36 is the answer! It's easy.