Multiplication of decimal fractions : Multiplication of decimal fractions Rule: shift the decimal place to the right by as many places of decimal as is the power of 10.
For eg:
4.7209 by 100
4.7209*100=472.09
0.3456 by 1000
0.3456*1000=345.6
For you to solve:
0.034 by 10000
0.11 by 100000
Multiplication of two or more decimals : Multiplication of two or more decimals Rule: multiply the given numbers considering them without decimal point. Now,in the product, the decimal point is marked off to obtain as many places of decimal as is the sum of number decimal places in the given numbers.
For eg:
1.71*1.2
171*12=2052
Sum of number of decimal places in the given number=(2+1)=3
So,1.71*1.2=2.052
Slide 3 : For eg:
3.764*11.4
3764
*114
---------
14984
3746*
3746**
-----------
427044
-----------
3746*114=427044
3.764*11.4=42.7044
For you to solve:
1)0.5*0.05*0.005*50=?
2)Given that 172*38=6536,find 1.72*0.38?
Division of decimal fraction by a counting number : Division of decimal fraction by a counting number Rule: divide the decimal numeral without considering the decimal point, by the given counting number. Now, in the quotient put the decimal point to give as many places of decimal as are tihere in dividend.
For eg:
Divide 0.49 by 7
49/7=7
Dividend contains two places of decimal
So,0.49/7=0.07
t : t For you to solve:
Divide 0.0182 by 14
Dividing a decimal fraction by decimal fraction
Rule: multiply both the dividend and the divisor by a suitable multiple of 10 so that divisor becomes a whole number.
For eg:
Eg1)25 by 0.05
25/0.05=(25*100)/(0.05*100)=2500/5=500
Eg2)0.00044 by 0.11
0.00044/0.11=(0.00044*100)/(0.11*100)=0.044/11=0.004
For you to solve:
1)40.40 by 0.0008
2)4.2 by 0.006
Comparison of fractions : Comparison of fractions Rule: convert each one of the given fractions in the decimal form. And now arrange them in ascending or descending order.
For eg:
Arrange in ascending order: 3/8,7/12,2/3,14/19,16/25,1/2
Converting them into fractions
3/8=0.375,7/12=0.583,2/3=0.666,14/19=0.736, 16/25=0.64 and ½=0.5
0.375<0.5<0.583<0.64<0.666<0.736
3/8< 1/2< 7/12< 16/25< 2/3< 14/19
Recurring decimal : Recurring decimal If in a decimal fraction,a figure or a set of figures is repeated continuously,then such a number is called a recurring decimal.
For eg:
2/3=0.66666……
1/7=0.142857 142857…….