There are some rules of dividing the decimal numbers. Different methods of division are applied in dividing the decimal numbers.
(1) Division of a decimal by a whole number:
Rules: (a) Divide as in division of numbers.
(b) When you reach the tenth digit, place the decimal in the quotient.
When the number of digits in the dividend is less and the division is not complete, keep adding zero at every step till the division is complete.
Example: (1) 100.4 ÷ 25
25)100.4(4.016
100_
40-------------- Put zero
25_
150------------ Put zero
150
X
(2) 1.2 ÷ 25
25)1.20(0.048
100_
200 Since 12 is not multiply of 25, so 0 is added.
200_
Xx
(2) Division by decimal numbers by 10, 100, 1000 etc.
Rules: (a) While dividing a decimal by 10, 100 or 1000 etc, multiples of 10 the decimal shifts to the left by as many places as there are zeros in the divisor.
(b) If the number of places in the integral part is less, then put the required number of zeros to the left of the integral part, then shift the decimal point.
Example: (a) 71.6 ÷ 10
= 716 ÷10
10
716 x 1_
= 10 10
= 716
100
= 7.16 Ans.
(b) 923.07 ÷ 100
92307 ÷ 100
100
= 92307 x 1__
100 100
= 92307
10000
= 9.2307 Ans.
Rules of Division of Decimal Numbers Continued
(3) Division of decimal numbers by multiples of 10, 100, 1000 etc.
Example: 245.1 ÷30
3)245.1(81.7
24___
x 5
3__
21
21_
X so, 245.1 ÷ 30 =8.17
245.1
30 = 245.1 = 245.1 x 1_
3x10 3 10
= 81.7 x 1
10 = 8.17 Ans.
(4) Division of a decimal by a decimal:
Example: 14.7 ÷ 2.1
147 ÷ 21
10 10
= 147 x 10
10 21
= 7 Ans.
Alternative method: (a) count the number of decimal digits in the divisor.
(b) Move the decimal in dividend that many places to right.
(c) Write the divisor without the decimal.
(d) Now divide the numbers as usual.
(5) Division of a whole number by a decimal:
Rules: (a) Count the number of decimal digits in the divisor.
(b) Add as many zeros to the dividend.
(c) Remove the decimal in the divisor.
(d) Divide as usual.
Example: 42 ÷ 0.7
42.0 ÷ 0.7
= 420 ÷ 7 = 60 Ans.
Exercise of Decimal Number Fractions
Divide: (1) 234.65 by 25
(2) 193.92 by 800
(3) 8.16 by 0.24
(4) 68 by 4.25
(5) 44 by 176
Answer: (1) 9.386 (2) 0.2424 (3) 34 (4) 16 (5) 0.25
(1) Division of a decimal by a whole number:
Rules: (a) Divide as in division of numbers.
(b) When you reach the tenth digit, place the decimal in the quotient.
When the number of digits in the dividend is less and the division is not complete, keep adding zero at every step till the division is complete.
Example: (1) 100.4 ÷ 25
25)100.4(4.016
100_
40-------------- Put zero
25_
150------------ Put zero
150
X
(2) 1.2 ÷ 25
25)1.20(0.048
100_
200 Since 12 is not multiply of 25, so 0 is added.
200_
Xx
(2) Division by decimal numbers by 10, 100, 1000 etc.
Rules: (a) While dividing a decimal by 10, 100 or 1000 etc, multiples of 10 the decimal shifts to the left by as many places as there are zeros in the divisor.
(b) If the number of places in the integral part is less, then put the required number of zeros to the left of the integral part, then shift the decimal point.
Example: (a) 71.6 ÷ 10
= 716 ÷10
10
716 x 1_
= 10 10
= 716
100
= 7.16 Ans.
(b) 923.07 ÷ 100
92307 ÷ 100
100
= 92307 x 1__
100 100
= 92307
10000
= 9.2307 Ans.
Rules of Division of Decimal Numbers Continued
(3) Division of decimal numbers by multiples of 10, 100, 1000 etc.
Example: 245.1 ÷30
3)245.1(81.7
24___
x 5
3__
21
21_
X so, 245.1 ÷ 30 =8.17
245.1
30 = 245.1 = 245.1 x 1_
3x10 3 10
= 81.7 x 1
10 = 8.17 Ans.
(4) Division of a decimal by a decimal:
Example: 14.7 ÷ 2.1
147 ÷ 21
10 10
= 147 x 10
10 21
= 7 Ans.
Alternative method: (a) count the number of decimal digits in the divisor.
(b) Move the decimal in dividend that many places to right.
(c) Write the divisor without the decimal.
(d) Now divide the numbers as usual.
(5) Division of a whole number by a decimal:
Rules: (a) Count the number of decimal digits in the divisor.
(b) Add as many zeros to the dividend.
(c) Remove the decimal in the divisor.
(d) Divide as usual.
Example: 42 ÷ 0.7
42.0 ÷ 0.7
= 420 ÷ 7 = 60 Ans.
Exercise of Decimal Number Fractions
Divide: (1) 234.65 by 25
(2) 193.92 by 800
(3) 8.16 by 0.24
(4) 68 by 4.25
(5) 44 by 176
Answer: (1) 9.386 (2) 0.2424 (3) 34 (4) 16 (5) 0.25
No comments:
Post a Comment