Line drawing multiplication

The number "2 1" is represented by a horizontal line, with two straight lines drawn above and 1 straight lines drawn below. The number "13" is represented by a vertical line, with 1 straight lines drawn on the left and 3 straight lines drawn on the right.

The calculation method is as follows: two straight lines in the upper left corner of the graph intersect with a straight line, and there are two intersections, which are recorded as 2; Three straight lines in the lower right corner intersect with a straight line, and there are three intersections, marked as 3; Similarly, the lower left corner and the upper right corner of the graph are marked as 1 and 6, respectively. 1 Add 6 to get 7, and the final result is 273.

② Take 2 1×3 1 as an example to draw a picture, as shown in the figure:

The number "2 1" is indicated by a horizontal line, with two lines drawn above and 1 line drawn below; The number "3 1" is represented by a vertical line, with three lines drawn on the left and 1 line drawn on the right.

Two straight lines in the upper left corner of the graph intersect with three straight lines, and there are six intersections, which are recorded as 6; There is an intersection in the lower right corner, marked as1; Similarly, the lower left corner is labeled 3 and the upper right corner is labeled 2. 3 plus 2 makes 5, and the final result is 65 1.

③ Draw with123x123, as shown in the figure:

Take 123x 1 23 as an example, as shown above: the first group of numbers "123" are represented by1,2 and 3 horizontal lines from top to bottom respectively; The second group of numbers "123" are represented by 1, 2 and 3 vertical lines from left to right, and then their intersections are counted and added in the direction indicated by the arrow in the figure. If it exceeds 10, it will advance by one place, and the final product will be 15 129.

Through the calculation of these three examples, we observe that the biggest advantage of line-drawing multiplication is that it is simple, interesting and intuitive, and it is not too difficult to master. However, this algorithm also has its limitations. When you come across a multiplication problem of large numbers, such as 987×789, think about that picture. People with intensive phobia are not good! Both line drawing algorithm and lattice algorithm can be used as interest expansion, and the most important thing is to master the conventional problem-solving methods.

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