Exercise 1.4

Exercise 1.4

1. Fill in the blanks.

(i) The nearest 100 of 843 is ___________. Answer: 800

(ii) The nearest 1000 of 756 is ___________. Answer: 1000

(iii) The nearest 10000 of 85654 is ___________. Answer: 90000

2. Say True or False.

(i) 8567 is rounded off as 8600 to the nearest 10. Answer: False

(ii) 139 is rounded off as 100 to the nearest 100.  Answer: True

(iii) 1,70,51,972 is rounded off as 1,70,00,000 to the nearest lakh. Answer: False

3. Round off the following to the given nearest place.

(i) 4,065; hundred

Solution: 4,065; hundred

Compare tenth place 6 > 5; Add ‘1’ to hundredth place and make tenth and oneth place as zero.

4,065; hundred = 6 > 5

= 4100

(ii) 44,555; thousand

Solution:

44,555 = 5 = 5 → 45,000

(iii) 86,943; ten thousand

Solution:

86,943 = 6 > 5 → 90,000

(iv) 50,81,739; lakh

Solution:

50,81,739 = 8 > 5 → 51,00,000

(v) 33,75,98,482; ten crore

Solution:

33,75,98,482 = 3 < 5 → 30,00,00,000

4. Estimate the sum of 157826 and 32469 rounded off to the nearest ten thousand .

Solution:

Sum of 157826 and 32469

Actual:

1,57,826

 32,469

1,90,295

157826 + 32469 = 1,90,295

Estimated sum = 1,60,000

nearest ten thousand = 30,000

                                    1,90,000

Hence Estimated sum of 157826 and 32469 = 1,90,000

5. Estimate by rounding off each number to the nearest hundred.

(i) 8074 + 4178

(ii) 1768977 + 130589

Solution:

(i) 8074 + 4178 

Estimate :

nearest hundred = 8100 + 4200

= 12,300

Hence estimated of 8074 + 4178 = 12,300

(ii) 1768977 + 130589

Estimate :

nearest hundred = 1768977 + 130589

= 1899600

Hence estimated of 1768977 + 130589 = 1899600

6. The population of a city was 43,43,645 in the year 2001 and 46,81,087 in the year 2011. Estimate the increase in population by rounding off to the nearest thousand.

Solution:

Population of city in 2001 = 43,43,645

in 2011 = 46,81,087

Estimate increase in population nearest to thousand is

Population of city in 2011 = 46,81,000

in 2001                              = 43,44,000

                                             3,37,000

Increase in population between 2011 to 2001 is 3,37,000

Objective Type Questions

7. The number which on rounding off to the nearest thousand gives 11000 is

(a) 10345

(b) 10855

(c) 11799

(d) 10056

Answer: (b) 10855

8. The estimation to the nearest hundred of 76812 is

(a) 77000

(b) 76000

(c) 76800

(d) 76900

Answer: (c) 76800

9. The number 9785764 is rounded off to the nearest lakh as

(a) 9800000

(b) 9786000

(c) 9795600

(d) 9795000

Answer: (a) 9800000

10. The estimated difference of 167826 and 2765 rounded off to the nearest thousand is

(a) 180000

(b) 165000

(c) 140000

 (d) 155000

Answer: (b) 165000

Answers:

Exercise 1.4

1) (i) 800 (ii) 1000 (iii) 90,000

2) (i) False (ii) True (iii) False

3) (i) 4100 (ii) 45,000 (iii) 90,000 (iv) 51,00,000 (v) 30,00,00,000

4) 1,90,000

5) (i) 12,300 (ii) 18,99,600

6) 3,37,000

7) (b) 10855

8) (c) 76800

9) (a) 9800000

10) (b) 165000