# NCERT Solutions for Class 7 Maths Chapter 2 Exercise 2.7

NCERT Solutions for Class 7 Maths Chapter 2 Exercise 2.7 (Ex. 2.7) Fractions and Decimals for CBSE and State board students updated for 2020-2021. All the question answers are done step by step using easier method, so that students of class 7 understand properly.

In class 7 math exercise 2.7 we will learn how the division of decimal number take place. Here we will divide natural numbers as well as decimal numbers from a decimal number.## Class 7 Maths Chapter 2 Exercise 2.7 Solution

Class: 7 | Mathematics |

Chapter: 2 | Fractions and Decimals |

Exercise: 2.7 | English and Hindi Medium Solution |

### CBSE NCERT Class 7 Maths Chapter 2 Exercise 2.7 Solution in Hindi and English Medium

### Class 7 Maths Chapter 2 Exercise 2.7 Solution in Videos

### Class 7 Maths Chapter 2 Exercise 2.7 Explanation

##### Multiplication of Decimals

Multiplication of a Decimal by 10, 100, 1000, etc.

Rules: (i) On multiplying a decimal by 10, the decimal point is shifted to the right by one place.

(ii) On multiplying a decimal by 100, the decimal point is shifted to the right by two places.

(iii) On multiplying a decimal by 1000, the decimal point is shifted to the right by three places, and so on.

##### Find the product: (i) 67.24 x 10 (ii) 4.956 x 100 (iii) 2.3748 x 1000

We have:

(i) 67.24 x 10 = 672.4 [shifting decimal point to the right by 1 place]

(ii) 4.956 x 100 = 495. 6 [shifting decimal point to the right by 2 places]

(iii) 2.3748 x 1000 = 2374.8 [shifting decimal point to the right by 3 places]

##### Multiplication of a Decimal by a Whole Number

Step 1. Multiple the decimal without the decimal point by the given whole number.

Step 2. Mark the decimal point in the product to have as many places of decimal as are there are in the given decimal.

##### Find the product: (i) 5.43 x 15 (ii) 0.327 x 12 (iii) 0.065 x 9

We have:

(i) 543 x 15 = 8145. (2 places of decimal)

So, 5.43 x 15 = 81.45.

(ii) 327 x 12 = 3924. (3 places of decimal)

So, 0.327 x 12 = 3.924.

(iii) 65 x 9 = 585. (3 places of decimal)

So, 0.0645 x 9 = 0.585.

##### Multiplication of a Decimal by a Decimal

Step 1. Multiply the two decimals without the decimal point just like whole numbers.

Step 2. Mark the decimal point in the product in such a way that the number of decimal places in the product is equal to the sum of the decimal places in the given decimals.

##### Multiply 73.68 by 5.4

First we multiply 7368 by 54.

7368 x 54

29472

368400

397872

#### Division of Decimals

Dividing a Decimal by 10, 100, 1000, etc.

Rules: (i) On dividing a decimal by 10, the decimal point is shifted to the left by one place.

(ii) On dividing a decimal by 100, the decimal point is shifted to the left by two places.

(iii) On dividing a decimal by 1000, the decimal point is shifted to the left by three places, and so on.

##### Divide: (i) 16.8 by 10 (ii) 236.4 by 100 (iii) 3709.6 by 1000

We have:

(i) 16.8 ÷ 10 = = 1.68 [shifting decimal point to the left by 1 place]

(ii) 236.4 ÷ 100 = = 2.364 [shifting decimal point to the left by 2 places]

(iii) 3709.6 ÷ 1000 = = 3.7096 [shifting decimal point to the left by 3 places]

##### Dividing A Decimal by a Whole Number

Step 1. Perform the division by considering the dividend a whole number.

Step 2. When the division of whole-number part of the dividend is complete, put the decimal point in the quotient and proceed with the division as in case of whole numbers.

##### 1 kg of milk has 0.264 kg of fat. How much fat in there is 12.5 kg of milk?

Quantity of fat in 1 kg of milk = (0.264 x 12.5) kg

= 3.3000 kg = 3.3 kg

Hence, the quantity of fat in 12.5 kg of milk is 3.3 kg.

##### What is the trick to multiplying decimals?

Multiply the numbers just as if they were whole numbers.

(i) Line up the numbers on the right – do not align the decimal points.

(ii) Starting on the right, multiply each digit in the top number by each digit in the (iii) bottom number, just as with whole numbers.

(iv) Add the products.

##### What important facts should you remember in multiplying decimals?

Multiplying decimals is the same as multiplying whole numbers except for the placement of the decimal point in the answer. When you multiply decimals, the decimal point is placed in the product so that the number of decimal places in the product is the sum of the decimal places in the factors.

##### Where do you move the decimal in multiplication?

To multiply decimals, first multiply as if there is no decimal. Next, count the number of digits after the decimal in each factor. Finally, put the same number of digits behind the decimal in the product.