If you do not have an electronic calculator, you may extract square
roots arithmetically as follows:
Suppose you want to extract the square root of 2,034.01. First, divide
the number into two-digit groups, working away from the decimal point.
Thus set off, the number appears as follows:
Next, find the largest number whose square can be contained in the
first group, This is the number 4, whose square is 16. The 4 is the
first digit of your answer. Place the 4 above the 20, and place its
square (16) under the first group, thus:
Now perform the indicated subtraction and bring down the next group to
the right, thus:
Next, double the portion of the answer already found (4, which doubled
is 8), and set the result down as the first digit of a new divisor,
thus:
The second digit of the new divisor is obtained by a trial-and-error
method. Divide the single digit 8 into the first two digits of the
remainder 434 (that is, into 43) until you obtain the largest number
that you can (1) add as another digit to the divisor and (2) use as a
multiplier which, when multiplied by the increased divisor, will produce
the largest result containable in the remainder 434. In this case, the
first number you try is 43 + 8, or 5. Write this 5 after the 8 and you
get 85. Multiply 85 by 5 and you get 425, which is containable in 434.
The second digit of your answer is therefore 5. Place the 5 above 34.
Your computation will now look like this:
Proceed as before to perform the indicated subtraction and bring down
the next group, thus:
Again double the portion of the answer already found, and set the
result (45 x 2, or 90) down as the first two digits of a new divisor
thus:
Proceed as before to determine the largest number that can be added as
a digit to the divisor 90 and used as a multiplier which, when
multiplied by the increased divisor, will produce a result containable
in the remainder, 901. This number is obviously 1. The increased divisor
is 901, and this figure, multiplied by the 1, gives a result exactly
equal to the remainder 901.
The figure 1 is therefore the third and final digit in the answer, The
square root of 2,034.01 is therefore 45.1
Your completed computation appears thus: