RD Sharma Class 7 Solutions Chapter 3 - Decimals (Ex 3.3) Exercise 3.3 - Free PDF
FAQs on RD Sharma Class 7 Solutions Chapter 3 - Decimals (Ex 3.3) Exercise 3.3
1. What are decimals and non-decimals in Class 7 maths?
Integers with a whole number part and a fractional part and both separated by a point are called a decimal number with the point known as a decimal. For example, 11.5 where the whole number 11 is separated from the fraction 5/10 by a decimal point. On the other hand, non-decimal is that number that has only the integer and no fraction part. Hence decimal is not used to separate the two parts. For example, 11 is a non-decimal number.
2. What are the types of decimal numbers in Exercise 3.3?
There are three different types of decimal numbers.
Exact decimal where the fraction part does not go on and ends with a zero reminder. For example 12.25. The number terminates two places after the decimal point.
Recurring decimal where the fraction does not terminate with a zero reminder instead a number repeats again and again forever. For example 13.333
Other decimals are like recurring decimals but not with the same repeating number that goes forever. The fraction does not terminate but it continues. For example 3.124324….
3. What are the rules of decimals you must follow to solve 3.3?
Decimals need to follow the following four rules.
Addition rule & Subtraction rule: It follows the basic principles of addition and subtraction.
Multiplication rule: The decimal numbers are multiplied in the same simple way as integers are multiplied. The only thing to note is the position of the decimal. The position of the decimal will be the position it has in the decimal number if only one of the multipliers is a decimal number. However, if two decimal numbers are multiplied then the sum of the positions is taken to place the decimal in the resulting answer. The position is counted from the right-hand side i.e. the fraction side and not from the whole number side. For example, if 2.2 is multiplied by 3.3 then the answer is 7.26 and not 72.6.
Division Rule: Division of a decimal by an integer follows the same division rule between two integers but the position of the decimal is the only thing to be noted. The position of the decimal will remain the same if one decimal number is divided by an integer. However, if one decimal is divided by another decimal first both the numerator and the denominator need to be multiplied by the same number with the denominator being a non zero number. For example, if 13.2 is divided by 0.22 then first divide both the numerator and the denominator by 10 since dividing both with the same number is an equivalent fraction. So 132 /2.2 is the same as 13.2/2.2. And now the result will be 60.0.
4. How to convert decimals to fractions and vice versa?
Fractions are sometimes easier to handle than decimals. The opposite situation may also happen. So we need to know how to convert one to the other.
Decimals to fractions can be easily converted with the concept that the number after the decimal point is a fraction. The number after the decimal point is the tenth, hundredth or so on. Hence if the number after the decimal is written in fraction of ten, hundred or so on and simplified to the lowest fraction we get the fraction. For example, the decimal 0.25 is the representation of
25/100 which is equivalent to ¼.
Fractions to decimals can easily be converted by dividing the numerator by denominator. For example, 2/4 is 0.5.
5. What is the importance of decimals in real life?
Decimals are very important to bring precision in a numerical value. To determine the exact money, marks, weight, the size we need decimals to bring accuracy. Only decimal can help us to understand whether the given number is greater or lesser than a particular integer. Students always want precision in their marks obtained which they often compare with their friends. This can only be possible with decimals. For example, if a student gets 98 out of 100 in maths it will be expressed as 98%.
