Class 6 NCERT Solutions - Knowing Our Number

1. Fill in the blanks: 
(a) 1 lakh = _______________ ten thousand
(b) 1 million = _______________ hundred thousand 
(c) 1 crore = _______________ ten lakh 
(d) 1 crore = _______________ million
(e) 1 million = _______________ lakh. 

2. Place commas correctly and write the numerals: 

(a) Seventry-three lakh seventy-five thousand three hundred seven. 
(b) Nine crore five lakh forty-one. 
(c) Seven crore fifty-two lakh twenty-one thousand three hundred two.
(d) Fifty-eight million four hundred twenty-three thousand two hundred two. 
(e) Twenty-three lakh thirty thousand ten. 

3. Insert commas suitable and write the names according to Indian system of numeration: 
(a) 87595762 
(b) 8546283 
(c) 99900046
(d) 9843270.

4. Insert commas suitable and write the names according to International system of numeration: 
(a) 78921092 
(b) 7452283 
(c) 99985102 
(d) 4804983. 

Answers:

1.  (a) 10  (b) 10 (c) 10  (d) 1 (e) 10 

2.  (a) 73,75,307 (c) 7,52,21,302 (e) 23,30,010  (b) 9,05,00,041 (d) 58,423,20. 
 

3.  (a) 8,75,95,762 → Eight crore seventy-five lakh ninety-five thousand seven hundred sixty-two (b) 85,46,283 → Eight-five lakh forty-six thousand two hundred eighty-three (c) 9,99,00,046 → Nine crore ninety-nine lakh forty-six (d ) 9,84,32,701 → Nine crore eighty-four lakh thirty-two thousand seven hundred on. 
 

4.  (a) 78,921,092 → Seventy-eight million nine hundred twenty-one thousand ninety-two (b) 7,452,483 → Seven million four hundred fifty-two thousand two hundred eighty-three (c) 99,985,102 → Ninety-nine million nine hundred eighty-five thousand one hundred two (d) 48,049,831 → Forty-eight million forty-nine thousand eight hundred thirty-on. 

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Question. 

1. A book exhibition was held for four days in a school. The number of tickets sold at the counter on the first, second, third and final day was respectively 1094, 1812, 2050 and 2751. Find the total number of tickets sold on all the four days.

2. Shekhar is a famous cricket player. He has so far scored 6980 runs in test matches. He wishes to complete 10,000 runs. How many more runs does he need?

3. In an election, the successful candidate registered 5,77,500 votes and his nearest rival secured
3,48,700 votes. By what margin did the successful candidate win the election?

4. Kirti Bookstore sold books worth ` 2,85,891 in the first week of June and books worth `
4,00,768 in the second week o the month. How much was the sale for the two weeks together? In which week was the sale greater and by how much?

5. Find the difference between the greatest and the least number that can be written using the digits 6, 2, 7, 4, 3 each only once.

6. A machine, on an average, manufactures 2,825 screws a day. How many screws did it produce in the month of January 2006?

7. A merchant had ` 78,592 with her. She placed an order for purchasing 40 radio sets at ` 1,200 each. How much money will remain with her after the purchase?

8. A student multiplied 7236 by 65 instead of multiplying by 56. By how much was his answer greater than the correct answer?

9. To stitch a shirt 2 m 15 cm cloth is needed. Out of 40 m cloth, how many shirts can be stitched and how much cloth will remain?

10. Medicine is packed in boxes, each weighing 4 kg 500 g. How many such boxes can be loaded in a can which cannot carry beyond 800 kg?

11. The distance between the school and the house of a student’s house is 1 km 875 m. Everyday she walks both ways. Find the total distance covered by her in six days.

12. A vessel has 4 liters and 500 ml of curd. In how many glasses each of 25 ml capacity, can it be filled. 

Answers:

1. Number of tickets sold on first day
= 1,094
Number of tickets sold on second day
= 1,812
Number of tickets sold on third day
= 2,050
Number of tickets sold on fourth day
= + 2,751
Total tickets sold
= 7,707
Therefore, 7,707 tickets were sold on all the four days. 

2. Runs to achieve
Runs scored
Runs required
Therefore, he needs 3,020 more runs.

3. Number of votes secured by successful candidates
= 5,77,500
Number of votes secured by his nearest rival
= – 3,48,700
Margin between them
= 2,28,800
Therefore, the successful candidate won by a margin of 2,28,800 votes.

4. Books sold in first week
= 2,85,891
Books sold in second week
= + 4,00,768
Total books sold
= 6,86,659
Since, 4,00,768,> 2,85,891
Therefore sale of second week is greater than that of first week.
Books sold in second week
= 4,00,768
Books sold in first week
= – 2,85,891
More books sold in second week
= 1,14,877
Therefore, 1,14,877 more books were sold in second week. 

5. Greatest five-digit number using digits 6,2,7,4,3
Smallest five-digit number using digits 6,2,7,4,3
Difference
Therefore the difference is 52965.

6. Number of screws manufactured in one day
Number of days in the month of January (31 days. = 10,000
= – 6,980
= 3,02. = 76432
= – 23467
= 5296. = 2,825
= 2,825 x 31
= 87,575
Therefore the machine produced 87,575 screws in the month of January. 

7. Cost of one radio
= ` 1200
Cost of 40 radios = 1200 x 40
= ` 48,000
Now,
Total money with merchant
= ` 78,592
Money spent by her
= – ` 48,000
Money left with her
= ` 30,592
Therefore, ` 30,592 will remain with her after the purchase. 

8. Wrong answer = 7236 x 65
7236 x 65
36180
43416 x

47034. Correct answer = 7236 x 56
7236 x 56
43416
36180 x

40521. Difference in answers = 470340 – 405216
= 65,124

9. Cloth required to stitch one shir. = 2 m 15 cm
= 2 x 100 cm + 15 cm
= 215 cm
Length of cloth = 40 m = 40 x 100 cm = 4000 cm
Number of shirts can be stitched
= 4000 ÷ 215
18
215 4000
− 215
1850
−1720
130
Therefore, 18 shirts can be stitched and 130 cm (1 m 30 cm) cloth will remain.

10. The weight of one box = 4 kg 500 g = 4 x 1000 g + 500 g = 4500 g
Maximum load can be loaded in van = 800 kg = 800 x 1000 g = 800000 g
Number of boxes = 800000 ÷ 450. 
  177
4500 800000
− 4500
35000
−31500
35000
−31500

350. Therefore, 177 boxes can be loaded.

11. Distance between school and home
= 1.875 km
Distance between home and school
= + 1.875 km
Total distance covered in one day
= 3.750 km
Distance covered in six days
= 3.750 x 6 = 22.500 km
Therefore, 22 km 500 m distance covered in six days.

12. Capacity of curd in a vessel = 4 liters 500 ml = 4 x 1000 ml + 500 ml = 4500 ml
Capacity of one glass = 25 ml
Number of glasses can be filled = 4500 ÷ 25
180
25 4500
− 25
200
−200
0
Therefore, 180 glasses can be filled by curd. 

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1. Estimate each of the following using general rule: (a) 730 + 998 (b) 796 – 314 (c) 12,904 + 2,888 (d) 28,292 – 21,49. 

2. Give a rough estimate (by rounding off to nearest hundreds) and also a closer estimate (by rounding off to nearest tens): (a) 439 + 334 + 4317 (b) 1,08,737 – 47,599 (c) 8325 – 491 (d) 4,89,348 – 48,36.

3. Estimate the following products using general rule: (a) 578 x 161 (b) 5281 x 3491 (c) 1291 x 592 (d) 9250 x 2. 

Answers:. 

1.  

(a) 730 round off to 700
998 round off to 1000
Estimated sum = 1700

(b) 796 round off to 800
314 round off to 300
Estimated sum = 500

(c) 12904 round off to 13000
2888 round off to 3000
Estimated sum = 1600.

(d) 28292 round off to
21496 round off to
Estimated difference. 28000
21000
7000
 

2. 

(a) 439 round off to
400
334 round off to
300
4317 round off to 4300
Estimated sum = 5000

(b) 108734 round off to
47599 round off to
Estimated difference . 108700
47600
61100

(c) 8325 round off to
8300
491 round off to
500
Estimated difference = 7800
 
(d) 489348 round off to
48365 round off to
Estimated difference . 489300
48400
440900

3.

(a) 578 x 161
578 round off to 600
161 round off to 200
The estimated product = 600 x 200 = 1,20,000 

(b) 5281 x 3491
5281 round of to 5,000
3491 round off to 3,500
The estimated product = 5,000 x 3,500 = 1,75,00,000 

(c) 1291 x 592
1291 round off to 1300
592 round off to 600
The estimated product = 1300 x 600 = 7,80,000

(d) 9250 x 29
9250 round off to 10,000
229 round off to 30
The estimated product = 10,000 x 30 = 3,00,00.