Page 32 - SM inner class 8.cdr

E xercise 3.3

Find the square root of the following.
144 169 784 1024
1. 2. 3. 4.
225 256 841 1225
34 1 41 24
5. 2 6. 6 7. 5 8. 12
81 4 64 25
67 136 92 196
9. 9 10.1 11. 101 12. 2517
121 225 169 289
Squares of Terminating Decimals Step 4. Place the dec i mal point in the
quo tient af ter 2 be cause the next
Example 28. Find the square root of 3881.29.
pair is a dec i mal part.
Solution:
Step 5. Bring down 29 to make 3729 the
Step 1. Beginning at the decimal point,
next div i dend. Dou ble 62 (the
make pairs of two to the left as we num ber in the quo tient) and place
do in number without decimal. the dou ble, i.e., 124 as the next
Now make pairs to the right of di vi sor as shown. Di vide 124 into
decimal in the same way but 372 to ob tain 3. Write 3 as the next
starting from right to left shown
num ber in the quo tient and also
by the arrow in the figure.
place 3 next to 124 in the di vi sor.
6 2 . 3 Mul ti ply 1243 by 3 and place the
prod uct un der 3729.
.
6 38 81 29
Sub tract. The re main der is zero.
+6 36
.
\ 3881 29 = 623
.
122 2 81 Example 29. Find the square root of 6432.04.
+2 –2 44
Solution: In the above example, since 16 does not
1243 37 29 divide 3, put a zero both in the root (quotient) and
37 29 the divisor and bring down the next pair 04 also.
8 0 . 2
0
.
8 64 32 04
Step 2. 6 is the largest whole-number +8 64
square root that is contained in 38 1602 32 04
which constitutes the first period. +2 32 04
Write 6 on top as quotient and also
0
in the divisor. Subtract 6 ´ 6 = 36
.
from 38. The remainder is 2. Therefore, 6432 04. = 80 2
Step 3. Bring down the next pair 81. Square Root of Numbers that are Not
Double 6 (the number in the Perfect Squares
quotient) and place the double, i.e.,
12 as the next divisor as shown. If we have to find the square root of a number
Divide 12 into 28 to obtain 2. Write up to ‘n’ places of decimals, the number of
2 as the next number in the digits in the decimal part must be 2n. If they
quotient and also place 2 next to are less than 2n, then affix suitable number of
12 in the divisor as shown. zeros to the extreme right of the decimal part.
Multiply 122 by 2 and place the Then, find the square root of decimal number
product under 281 and subtract.
using long division method.
The remainder is 37.
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Mathematics In Focus - 8