Multiplication Trick

How to multiply numbers visually.

Suppose you want to multiply 22 by 13. Draw 2 lines slanted upward to the right, and then move downward to the right a short distance and draw another 2 lines upward to the right. Then draw 1 line slanted downward to the right, and then move upward to the right a short distance and draw another 3 lines slanted downward to the right.

Now count up the number of intersection points in each corner of the figure. The number of intersection points at left will be the first digit of the answer. Sum the number of intersection points at the top and bottom of the square; this will be the middle digit of the answer. The number of intersection points at right will be the last digit of the answer.