RS Aggarwal Solutions Class 6 Ex 1B

Estimate each of the following products by rounding off each number to the nearest ten:

 

Question 1:

38 x 63

Solution:

38 estimated to the nearest ten = 40

63 estimated to the nearest ten = 60

Therefore, The required estimation = (40 x 60) = 2400

 

Question 2:

54 x 47

Solution:

54 estimated to the nearest ten = 50

47 estimated to the nearest ten = 50

Therefore, The required estimation = (50 x 50) = 2500

 

Question 3:

28 x 63

Solution:

28 estimated to the nearest ten = 30

63 estimated to the nearest ten = 60

Therefore, The required estimation = (30 x 60) = 1800

 

Question 4:

42 x 75

Solution:

42 estimated to the nearest ten = 40

75 estimated to the nearest ten = 80

Therefore, The required estimation = (40 x 80) = 3200

 

Question 5:

64 x 58

Solution:

64 estimated to the nearest ten = 60

58 estimated to the nearest ten = 60

Therefore, The required estimation = (60 x 60) = 3600

 

Question 6:

15 x 34

Solution:

15 estimated to the nearest ten = 20

34 estimated to the nearest ten = 30

Therefore, The required estimation = (20 x 30) = 600

Estimate each of the following products by rounding off each number to the nearest hundred:

 

Question 7:

376 x 123

Solution:

376 estimated to the nearest hundred = 400

123 estimated to the nearest hundred = 100

Therefore, The required estimation = (400 x 100) = 40000

 

Question 8:

264 x 147

Solution:

264 estimated to the nearest hundred = 300

147 estimated to the nearest hundred = 100

Therefore, The required estimation = (300 x 100) = 30000

 

Question 9:

423 x 158

Solution:

423 estimated to the nearest hundred = 400

158 estimated to the nearest hundred = 200

Therefore, The required estimation = (400 x 200) = 80000

 

Question 10:

509 x 179

Solution:

509 estimated to the nearest hundred = 500

179 estimated to the nearest hundred = 200

Therefore, The required estimation = (500 x 200) = 100000

 

Question 11:

392 x 138

Solution:

392 estimated to the nearest hundred = 400

138 estimated to the nearest hundred = 100

Therefore, The required estimation = (400 x 100) = 40000

 

Question 12:

271 x 339

Solution:

271 estimated to the nearest hundred = 300

339 estimated to the nearest hundred = 300

Therefore, The required estimation = (300 x 300) = 90000

 

Estimate each of the following products by rounding off the first number upwards and the second number downwards:

 

Question 13:

183 x 154

Solution:

183 estimated upwards = 200

154 estimated downwards = 100

Therefore, The required product = (200 x 100) = 20000

 

Question 14:

267 x 146

Solution:

267 estimated upwards = 300

146 estimated downwards = 100

Therefore, The required product = (300 x 100) = 30000

 

Question 15:

259 x 76

Solution:

359 estimated upwards = 400

76 estimated downwards = 70

Therefore, The required product = (400 x 70) = 28000

 

Question 16:

472 x 158

Solution:

472 estimated upwards = 500

158 estimated downwards = 100

Therefore, The required product = (500 x 100) = 50000

 

Question 17:

680 x 164

Solution:

680 estimated upwards = 700

164 estimated downwards = 100

Therefore, The required product = (700 x 100) = 70000

 

Question 18:

255 x 350

Solution:

255 estimated upwards = 300

350 estimated downwards = 300

Therefore, The required product = (300 x 300) = 90000

 

Estimate each of the following products by rounding off the first number downwards and the second number upwards:

Question 19:

356 x 278

Solution:

356 estimated downwards = 300

278 estimated upwards = 300

Therefore, The required product = (300 x 300) = 90000

 

Question 20:

472 x 76

Solution:

472 estimated downwards = 400

76 estimated upwards = 80

Therefore, The required product = (400 x 80) = 32000

 

Question 21:

578 x 369

Solution:

572 estimated downwards = 500

369 estimated upwards = 400

Therefore, The required product = (500 x 400) = 200000

 

Find the estimated quotient for each of the following:

 

Question 22:

87 \(\div\) 28

Solution:

87 \(\div\) 28 is approximately equal to 90 \(\div\) 30 = 3.

 

Question 23:

83 \(\div\) 17

Solution:

The estimated quotient for 83 \(\div\) 17 is approximately equal to 80 \(\div\) 20 = 8 \(\div\) 2 = 4.

 

Question 24:

75 \(\div\) 23

Solution:

The estimated quotient of 75 \(\div\) 23 is approximately equal to 80 \(\div\) 20 = 8 \(\div\) 2 = 4.

 

Question 25:

193 \(\div\) 24

Solution:

The estimated quotient of 193 \(\div\) 24 is approximately equal to 200 \(\div\) 20 = 20 \(\div\) 2 = 10.

 

Question 26:

725 \(\div\) 23

Solution:

The estimated quotient of 725 \(\div\) 23 is approximately equal to 700 \(\div\) 20 = 70 \(\div\) 2 = 35.

 

Question 27:

275 \(\div\) 25

Solution:

The estimated quotient of 275 \(\div\) 25 is approximately equal to 300 \(\div\) 30 = 30 \(\div\) 3 = 10.

 

Question 28:

633 \(\div\) 33

Solution:

The estimated quotient of 633 \(\div\) 33 is approximately equal to 600 \(\div\) 30 = 60 \(\div\) 3 = 20.

 

Question 29:

729 \(\div\) 29

Solution:

729 \(\div\) 29 is approximately equal to 700 \(\div\) 30 or 70 \(\div\) 3, which is approximately equal to 23.

 

Question 30:

858 \(\div\) 39

Solution:

858 \(\div\) 39 is approximately equal to 900 \(\div\) 40 or 90 \(\div\) 4, which is approximately equal to 23.

 

Question 31:

868 \(\div\) 38

Solution:

868 \(\div\) 38 is approximately equal to 900 \(\div\) 40 or 90 \(\div\) 4, which is approximately equal to 23.


Practise This Question

The silk covering over caterpillar is known as