- We have learnt about fractions and decimals along with the operations of addition and subtraction on them, in the earlier class.
- We now study the operations of multiplication and division on fractions as well as on decimals.
- We have learnt how to multiply fractions. Two fractions are multiplied by multiplying their numerators and denominators seprately and writing the product as product of numerators by product of denominators. For example,
. - A fraction acts as an operator ‘of ’. For example,
of 2 is 
.
(a) The product of two proper fractions is less than each of the fractions that are multiplied.
(b) The product of a proper and an improper fraction is less than the improper fraction and greater than the proper fraction.
(c) The product of two improper fractions is greater than the two fractions. - A reciprocal of a fraction is obtained by inverting it upside down. We have seen how to divide two fractions.
(a) While dividing a whole number by a fraction, we multiply the whole number with the reciprocal of that fraction. For example,
.
(b) While dividing a fraction by a whole number we multiply the fraction by the reciprocal of the whole number. For example,
.
(c) While dividing one fraction by another fraction, we multiply the first fraction by the reciprocal of the other. So,
. - We also leant how to multiply two decimal numbers. While multiplying two decimal numbers, first multiply them as whole numbers. Count the number of digits to the right of the decimal point in both the decimal numbers. Add the number of digits counted. Put the decimal point in the product by counting the digits from its rightmost place. The count should be the sum obtained earlier. For example,
. - To multiply a decimal number by 10, 100 or 1000, we move the decimal point in the number to the right by as many places as there are zeros over 1. Thus,
, 
, 
.
- We have seen how to divide decimal numbers.
(a)To divide a decimal number by a whole number, we first divide them as whole numbers. Then place the decimal point in the quotient as in the decimal number. For example,
.
Note that here we consider only those divisions in which the remainder is zero.
(b)To divide a decimal number by 10, 100 or 1000, shift the digits in the decimal number to the left by as many places as there are zeros over 1, to get the quotient. So,
, 
, 
.
(c) While dividing two decimal numbers, first shift the decimal point to the right by equal number of places in both, to convert the divisor to a whole number. Then divide. Thus,
.
For More :-
CBSE
Class–VII | CHAPTER – 1 Integers | NMMS
Revision Notes à Click Here
Tracing
Changes Through a Thousand Years | NMMS Revision Notes | Class 7 | Social à Click Here
New
Kings and Kingdoms | NMMS Revision Notes | Class 7 | Social à Click Here
The
Delhi Sultanate | NMMS Revision Notes | Class 7 Social à Click Here
The
Mughal Empire | NMMS Revision Notes | Class 7 Social à Click Here
Tribes
Nomads and Settled Communities | NMMS Revision Notes | Class 7 Social à Click Here
Devotional
Paths to the Divine | NMMS Revision Notes | Class 7 Social à Click Here
The
Making of Regional Cultures | NMMS Revision Notes | Class 7 Social à Click Here
Eighteenth
Century Political Formations | NMMS Revision Notes | Class 7 Social à Click Here
Environment
| NMMS Revision Notes | Class 7 Social à Click Here
Inside
Our Earth | NMMS Revision Notes | Class 7 Social à Click Here
Our
Changing Earth | NMMS Revision Notes | Class 7 Social à Click Here
Air |
NMMS Revision Notes | Class 7 Social à Click Here
Water
| NMMS Revision Notes | Class 7 Social à Click Here
Human
Environment Interactions the Tropical | NMMS Revison Notes | Class 7 Social à Click Here
Life
in the Deserts | NMMS Revision Notes | Class 7 Social à Click Here
On
Equality | NMMS Revision Notes | Class 7 Social à Click Here
How
the State Government Works | NMMS Revision Notes | Class 7 Social à Click Here
Role
of the Government in Health | NMMS Revision Notes | Class 7 Social à Click Here
Growing
up as Boys and Girls | NMMS Revision Notes | Class 7 Social à Click Here
Women
Change the World | NMMS Revision Notes | Class 7 Social à Click Here
Understanding
Media | NMMS Revision Notes | Class 7 Social à Click Here
Markets
Around Us | NMMS Revision Notes | Class 7 Social à Click Here
A
Shirt in the Market | NMMS Revision Notes | Class 7 Social à Click Here
Nutrition
in Plants | NMMS Revision Notes | Class 7 Science à Click Here
Nutrition
in Animals | NMMS Revision Notes | Class 7 Science à Click Here
Heat |
NMMS Revision Notes | Class 7 Science à Click Here
Acids
Bases And Salts | NMMS Revision Notes | Class 7 Science à Click Here
Physical
And Chemical Changes | NMMS Revision Notes | Class 7 Science à Click Here
Respiration
In Organisms | NMMS Revision Notes | Class 7 Science à Click Here
Transportation
in Animals and Plants | NMMS Revision Notes | Class 7 Science à Click Here
Force
and Pressure | NMMS Quick Revision Notes
| Class: 8 Physics Ã
Click Here
Reproduction
In Plants | NMMS Revision Notes | Class 7 Science à Click Here
Motion
And Time | NMMS Revision Notes | Class 7 Science à Click Here
Electric
Current and its Effects | NMMS Revision Notes | Class 7 Science à Click Here
Light
| NMMS Revision Notes | Class 7 Science à Click Here
Waste
Water Story | NMMS Revision Notes | Class 7 Science à Click Here
How
When and Where | NMMS Revision Notes | Class 8 Social à Click Here
From
Trade to Territory | NMMS Revision Notes | Class 8 Social à Click Here
Ruling
the Countryside | NMMS Revision Notes | Class 8 Social à Click Here
Tribals
Dikus and Vision of Golden Age | NMMS Revision Notes | Class 8 Social à Click Here
When
People Rebel | NMMS Revision Notes | Class 8 Social à Click Here
Weavers
Iron Smelters and Factory Owners | NMMS Revision Notes | Class 8 Social à Click Here
Civilising
the Native Educating the Nation | NMMS Revision Notes | Class 8 Social à Click Here
Women
Caste and Reform | NMMS Revision Notes | Class 8 Social à Click Here
No comments:
Post a Comment