Japanese Multiplication Trick

Hey guys,
Sorry it's been almost 2 years since my last post. These last several months, I've been very busy with my classes and outside activities. But today, I hope my visual method of multiplying numbers makes up for this delay.

This is a method used by the Japanese on how to multiply two numbers visually using diagonal lines! It's very interesting, and I thought it would be worthwhile to share it with you today.

Problem: 12 x 13

Step 1: "Draw" the first number
Draw diagonal lines from left to right angling downwards representing the number 12. One diagonal line (tens place) should be by itself, and the other two (ones place) should be grouped together just a little bit farther up and away, as shown below.

Step 2: "Draw" the second number.
Draw diagonal lines from left to right angling upwards representing the number 13. One diagonal line (tens place) should be by itself, and the other three (ones place) should be grouped together just a bit farther down and away, as shown below. Keep in mind that these lines must intersect with the previously drawn ones.

Step 3: Group the intersections

Group the black and green line intersections depending on however they line up with each other. Refer to the diagram below.

Step 4: Count the intersections.

Count the number of intersections in each group from right to left. The number of intersections on the farthest right would be the ones place, the number to the left of that would be the tens place, and so on. The number of intersections are actually the digits that make up the product of the original problem. Once you have the digits, you have your answer.

Therefore, the answer to 12 x 13 = 156. 

This method can be used to find the product of any ANY TWO NUMBERS. The only difference is that the intersections may be grouped up differently, and the number of intersections in each group may exceed 9. If this occurs, simply carry it over to the next left place value in the final answer. 

Hope this helps! I do look forward to being active on my blog once again. Feel free to leave your comments below or follow my blog. Thanks!