How to calculate multiplication formula quickly?
The quick memorization methods of multiplication formula are: vertical memorization, horizontal memorization, back flipping and understanding memorization. 1, upright back. For example, one gets one, one gets two, until 1999, then two gets four, two gets six, until 298, then three gets nine, and three gets twelve, until 3927, and so on, and then in turn, there are 446 columns, 5525 columns, 636 columns, 749 columns and 89 columns. There is a rule in this method, that is, the number of digits in the vertical column increases gradually, which can help memory. 2. Cross your back. For example, the first rampage leads to one sentence; The second rampage, two sentences lead to one sentence; The second rampage, two sentences lead to two sentences; The second rampage, two sentences lead to four sentences; And so on; In the first few lines, only a few sentences lead to nine; And the last nine sentences, from 199 to 998 1. There is another rule in this method. In the first few lines, the last sentence is a few more than the previous one. Step 3 turn around. For example, recite one, two, then two, two, two, three, six, eight until 298, then go back to one, three, three, three, nine, then go down to three, four, twelve, until three, nine, twenty-seven, and so on, go back to one, four, and then turn. One of the characteristics of this recitation is that there are nine sentences in the formula from one to nine, and several formulas will gradually increase. 4. Understand the mnemonic method. Comprehensive memory needs some reference, that is, the formula you are familiar with. For example: 25 10/0,9981etc. Taking these formulas as reference objects, the adjacent multiplication formulas can be found quickly through calculation. If you can't figure out the result of 8×9, you can think of "9 9 minus 1 9", that is, "8 1-9=72". Of course, you can't write 72 after reaching a conclusion, but you should also recite the formula of "8×9" in your mind. After so many times of thinking, the sentence "8972" will also become a memorable sentence.