How to quickly memorize the multiplication table?
Characteristics of the formula
Editing
1. The nine-nine table generally only uses nine numbers from one to nine.
2. The nine-nine table includes the commutability of multiplication, so only eight nine seventy-two is needed, and "nine eight seventy-two" is not needed. 9 times 9 has 81 sets of products, and the nine-nine table only needs It requires 1+2+3+4+5+6+7+8+9 = 45 terms. The abacus in the Ming Dynasty also used the nine-nine table with 81 sets of products. The nine-nine table with 45 items is called the small nine-nine, and the nine-nine table with 81 items is called the big nine-nine.
3. The shortest multiplication table in the ancient world. The Mayan multiplication table requires 190 items, the Babylonian multiplication table requires 1770 items, and the multiplication tables of Egypt, Greece, Rome, India and other countries require infinite items; the 99 table only needs 45/81 items.
4. There is a rhythm when reading aloud, making it easy to memorize the entire table.
5. The Nine-Nine Watch has existed for at least three thousand years. It has been used in calculations since the Spring and Autumn Period and the Warring States Period, and was improved and used in abacus in the Ming Dynasty. The nine-nine table is also a basic skill in primary school arithmetic.
6. Another nine:
9X9=81 8+1=9
9X8=72 7+2=9
9X7=63 6+3=9
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9X2=18 1+8= 9
9X1=9 9=9
Multiplication table shorthand? (Note: Only the multiplication formulas from 1 to 9 are required)
The multiplication formulas for nine are particularly difficult to remember. You can mobilize the whole family to come up with clever ways to use these formulas.
For example: 1. Find patterns and compare notes: such as five nine forty-five and six nine fifty-four, seven nine sixty-three and four nine thirty-six, etc. 2. Use stories to remember: Tang Monk went through eighty-one difficulties, Sun Wukong had eighty-nine and seventy-two transformations, while Zhu Bajie only had half of his magic power and had forty-nine and thirty-six transformations.
3. Use homophones to remember: My uncle is eighty-one years old (nine-nine-eighty-one) 4. Observe the origins of the ones and tens: the number multiplied by nine, the tens is the number minus 1, the number The digit is the number in the nine minus ten digit, such as four nine thirty six. When you memorized the formula, did you find any rules in the multiplication formula of 9? How to memorize the "multiplication table of 9"? ①The ones digit is from big to small, and the tens digit is from small to big.
Remember four-nine-thirty-six, what can you think of five-nine? How much can you think about thirty-nine? Why does this happen? Because 9 is added to both. It is very important for children to understand the relationship between the two sentences before and after! ②Group rules.
Let’s observe the products of the “9 multiplication formula”. Except for “one nine equals nine”, what are the relationships between the other products? For example: two hundred and ninety-eight, 18, ninety-nine and eighty-one, 81, two-digit single-digit numbers and tens-digit numbers have exchanged positions. Can you still find a few sets of such formulas? Three nine twenty-seven, 27; eighty-nine seventy-two, 72; four-nine-thirty-six, 36; seven-nine-sixty-three, 63; five-nine-forty-five, 45; six-nine-fifty-four, 54. Master this feature, and sometimes you don't need to memorize it from beginning to end. If you remember "two and ninety-eight", you will remember every sentence.
(Nine-nine-eighty-one) ③The number of 9 also has this rule: 1 9, 1 less than 10, is 9, 2 9s, 2 less than 20, is 18, 3 9 9s, 3 less than 30, is 27, ... 9 9s, 9 less than 90, are 81. This rule can also help us memorize the multiplication formula of 9, such as seventy-nine ( ), which is 7 less than 70, that is, 70 — 7 = 63, seventy-nine and sixty-three.
④ Carefully observe the products of the multiplication formulas of 9. Except for 9, they are all two-digit numbers. For these two-digit numbers, what is the sum of the numbers in the tens place and the numbers in the ones place? Features? (The numbers in the tens place and the numbers in the tens place add up to 9, 1+8=9, 2+7=9,..., 8+1=9) ⑤ "9 multiplication table" and our hands There is also a very special rule, so we can also use the "finger memory method" to help us memorize the multiplication formula of 9. Using 10 fingers to memorize it, students will be interested and remember it! Please stretch out your hands. When memorizing the formula "one nine makes nine", we can bend the little finger of our left hand. There are 9 fingers on the right side of the bent finger. The "9" here represents the 9 in the product; Similarly, when memorizing "Two Ninety-Eight", bend the ring finger of your left hand. On the left side of the bent finger, there is a heel finger. The "1" here represents the number 1 in the tens place in the product. On the right side of the bent finger, there are 8 fingers. Fingers, the "8" here represents the number 8 on each digit in the product, which is "twenty-nine-eight". Counting from left to right, the number on which finger is bent indicates the number of nines. The left side of the bent finger indicates the number in the tens place of the product, and the right side indicates the number in the units place of the product.
Is there a shorthand for multiplication tables?
There are 1. Multiply a dozen by a dozen: formula: multiply the head by the head, add the tail by the tail, and multiply the tail by the tail. Example: 12*14=?1*1=12+4=62*4=812 *14=168 Note: When multiplying the ones digits, if there are not enough two digits, use 0 as a placeholder. 2. The heads are the same and the tails are complementary (the sum of the tails equals 10): Formula: after adding 1 to a head, multiply the head by the head and multiply by the tail Tail. Example: 23*27=?2+1=3 2*3=6 3*7=2123*27=621 Note: Multiply the ones digits, if there are not enough two digits, use 0 as placeholder. 3. The first one The multipliers are complementary, and the other multiplier has the same number: Formula: After adding 1 to a head, multiply the head by the head and the tail by the tail. Example: 37*44=?3+1=44*4=167*4=2837*44= 1628 Note: When multiplying the ones digits, if there are not enough two digits, use 0 as a placeholder. 4. Multiply tens of one by tens of one: formula: multiply the head by the head, add the head by the head, and multiply the tail by the tail. Example: 21*41=?2 *4=82+4=61*1=121*41=861 5.11 Multiply any number: formula: the head and tail do not move and the sum in the middle drops down. Example: 11*23125=?2+3=53+1=41+ 2=32+5=72 and 5 are at the beginning and end respectively 11*23125=254375 Note: If the sum reaches ten, add one. 6. Multiply any number by more than ten: formula: the first position of the second multiplier does not move downwards, the number of the first factor Multiply each digit after the second factor, add the next digit, and then drop down. Example: 13*326=? 13 digits are 33*3+2=113*2+6=123*6=1813* 326=4238 Note: If the sum reaches ten, add one.
How to help children quickly memorize multiplication formulas
How to help children quickly memorize multiplication formulas, such as the multiplication formula for nine, two ninety-eight, three ninety-eight, three ninety-seven, four ninety-three Sixteen, five nine forty-five, six nine fifty-four... From the formula of nine, we can see that the sum of the products of each formula is nine, and the first factor in each formula is greater than the tenth digit. The product above is one big.
Take Five Nine Forty-Five as an example! Their product four plus five equals nine, and the first factor five is one greater than the product four in the tens place. This discovery gave Dad a revelation.
Based on this principle, my father made a "playing card multiplication table" by himself. Dad first cut out ten small squares from the calendar paper, and then wrote two adjacent numbers on both sides of the calendar paper in the same direction, such as 2 and 3, 3 and 4... Dad used this special pair of playing cards. The card performed a little magic trick on me, asking me to pick a card at random, and he immediately said the secret.
No matter how I choose, Dad can always get the answer right in one go. I was so surprised that I pestered my father to tell me the secret.
Dad told me his method, and I tried it. Hey, it really works. With my father's help, I learned the multiplication tables by heart.
Dad’s method is not only easy to remember, but also adds a lot of fun to me. I also recommend this method to my classmates as part of recess games.
Since then, I have become more and more interested in mathematics. I think that to learn mathematics well, you cannot just rely on rote memorization. You should also look for more tips and have more fun.
How to memorize multiplication formulas very easily
Memorize them sideways
For example, if the first horizontal line is one sentence, one will get one; the second horizontal row will be two sentences, one or two will be Two, two two is four; and so on, the lines are several sentences, and the last nine sentences are from one nine to nine to nine nine eighty-one. There is also a rule for this method. The next sentence will be increased by a certain number compared to the previous sentence.
The elves of the Understanding tribe are good at logical reasoning. After they can read the formulas in order, they will inevitably have some formulas that they are familiar with, such as: two five ten, nine nine eighty one, etc. Using these formulas as reference objects, they can use the method of calculation to quickly find the corresponding formulas. The adjacent multiplication formula, for example: if you can’t think of the result of 8*9, you can think of “9 9s minus one 9”, that is, “81-9=72”. Of course, you cannot write 72 after reaching the conclusion. Forget it, you should still recite the mantra "8*9" silently in your heart. After thinking about it several times, the mantra "eight, nine, seventy-two" will become a mantra that will be engraved in your heart. In this way, from a few formulas to all formulas, the effect should be more obvious. There are also schema memory methods, list memory methods, and jingle memory methods.