2. Find the complete square number not greater than the first number on the left, which is the "quotient";
3. Subtract the quotient from the first part on the left and write their difference in the second part on the right as the first remainder;
4. Multiply the quotient by 20 and try to divide it by the first remainder to get the largest integer as the trial quotient (if this largest integer is greater than or equal to 10, use 9 or 8 as the trial quotient);
5. multiply the quotient by 20, add the quotient, and then multiply the quotient. If the product obtained is less than or equal to the remainder, write this trial quotient after the quotient as a new quotient; If the obtained product is greater than the remainder, try again by reducing the trial quotient until the product is less than or equal to the remainder;
6. In the same way, keep asking.
The method of writing a square mentioned above is given by most of us in the appendix of the textbook when we are at school, which is too troublesome to practice. We can take the following measures, not afraid of a certain step in actual calculation! ! ! And the above method is not feasible.
For example, the number 136 16 1. First, we find a number close to the square root of 136 16 1. Choose any number between 300 and 400, and choose 350 as the representative.
We calculate 0.5 * (350+136161/350) and get 369.5.
Then we calculate 0.5 * (369.5+136161/369.5) and get 369.0003. We found that 369.5 is almost the same as 369.0003, and the number at the end of 369 2 is 1. We can reasonably conclude that 369 2 =136161.
Generally speaking, if you can write a prescription, you can use the above method to calculate the basic results once or twice. Another example: calculate the square root of 469225. First, we found that 600 2
0.5*(650+469225/650) to get 685.9. There is only 685 2 near 685, and the last number is 5, so 685 2 = 469225.
For those inexhaustible numbers, the accuracy of two or three calculations in this way is considerable, generally reaching several decimal places.
In fact, this algorithm is also an algorithm used by computers to find roots.