 Use Your Fingers to Multiply by 9

 1st: Number the
digits
of your hands from left to right.

 2nd: Bend the finger named by the number you wish to multiply.
 Ex. Multiply 4 x 9. The forth finger must be bent.

 3rd: Count the digits to the left of the bent finger.
 Count the digits to the right of the bent finger.
 These are the digits of the
product.
 Ex. 3 then 6, so, 4 x 9 = 36.

