Page 18 - NCERT Books

106 MATHEMATICS

4 (i.e., 64) on every pair of digits beginning with the first decimal place. Proceed

4 17.64 as usual. We get 17.64.
– 16 Step 2 Now proceed in a similar manner. The left most bar is on 17 and 4 < 17 < 5 .
2
2
1 Take this number as the divisor and the number under the left-most bar as the
dividend, i.e., 17. Divide and get the remainder.
4
4 17.64 Step 3 The remainder is 1. Write the number under the next bar (i.e., 64) to the right of
– 16 this remainder, to get 164.
8_ 1 64
4.2
4. Step 4 Double the divisor and enter it with a blank on its right.
4 17.64
4 17.64 Since 64 is the decimal part so put a decimal point in the – 16
– 16 quotient.
82 164
82 164 Step 5 We know 82 × 2 = 164, therefore, the new digit is 2.
– 164
Divide and get the remainder.
0
Step 6 Since the remainder is 0 and no bar left, therefore 17.64 = 4.2 .

Example 13: Find the square root of 12.25.
Solution: 3.5
3 12.25
– 9
Therefore, 12.25 = 3.5
65 325
325
0

Which way to move
Consider a number 176.341. Put bars on both integral part and decimal part. In what way
is putting bars on decimal part different from integral part? Notice for 176 we start from
the unit’s place close to the decimal and move towards left. The first bar is over 76 and the
second bar over 1. For .341, we start from the decimal and move towards right. First bar
is over 34 and for the second bar we put 0 after 1 and make .3410 .

2
48 Example 14: Area of a square plot is 2304 m . Find the side of the square plot.
4 2304 Solution: Area of square plot = 2304 m 2
–16 Therefore, side of the square plot = 2304 m
88 704
We find that, = 48
704 2304
0 Thus, the side of the square plot is 48 m.
Example 15: There are 2401 students in a school. P.T. teacher wants them to stand
in rows and columns such that the number of rows is equal to the number of columns. Find
the number of rows.