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

Aquatic organisms have: