NCERT Solutions for Chapter 1 Knowing our Numbers Class 6 Maths
Chapter Name  Knowing our Numbers NCERT Solutions 
Class  CBSE Class 6 
Textbook Name  Maths 
Related Readings 

Question 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
Solution
(a) 10
(b) 10
(c) 10
(d) 10
(e) 10
Question 2: Place commas correctly and write the numerals:
(a) Seventythree lakh seventyfive thousand three hundred seven.
(b) Nine crore five lakh fortyone.
(c) Seven crore fiftytwo lakh twentyone thousand three hundred two.
(d) Fiftyeight million four hundred twentythree thousand two hundred two.
(e) Twentythree lakh thirty thousand ten.
Solution
(a) 73,75,307
(b) 9,05,00,041
(c) 7,52,21,302
(d) 58,423,202
(e) 23,30,010
Question 3: Insert commas suitable and write the names according to Indian system of numeration:
(a) 87595762
(b) 8546283
(c) 99900046
(d) 98432701
Solution
(a) 8,75,95,762
Eight crore seventyfive lakh ninetyfive thousand seven hundred sixtytwo.
(b) 85,46,283
Eightfive lakh fortysix thousand two hundred eightythree.
(c) 9,99,00,046
Nine crore ninetynine lakh fortysix.
(d) 9,84,32,701
Nine crore eightyfour lakh thirtytwo thousand seven hundred one.
Question 4: Insert commas suitable and write the names according to International system of numeration:
(a) 78921092
(b) 7452283
(c) 99985102
(d) 48049831
Solution
(a) 78,921,092
Seventyeight million nine hundred twentyone thousand ninetytwo
(b) 7,452,483
Seven million four hundred fiftytwo thousand two hundred eightythree
(c) 99,985,102
Ninetynine million nine hundred eightyfive thousand one hundred two
(d) 48,049,831
Fortyeight million fortynine thousand eight hundred thirtyone
Exercise 1.2
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.
Solution
Question 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?
Solution
Question 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?
Solution
Question 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 of the month. How much was the sale for the two weeks together? In which week was the sale greater and by how much?
Solution
Since, 4,00,768,> 2,85,891Therefore sale of second week is greater than that of first week.
Therefore, 1,14,877 more books were sold in second week.
Question 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.
Solution
Therefore the difference is 52965.Question 6: A machine, on an average, manufactures 2,825 screws a day. How many screws did it produce in the month of January 2006?
Solution
Therefore, the machine produced 87,575 screws in the month of January.Question 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?
Solution
Now,Therefore, ₹ 30,592 will remain with her after the purchase.
Question 8: A student multiplied 7236 by 65 instead of multiplying by 56. By how much was his answer greater than the correct answer?
Solution
Wrong answer = 7236 × 65
Correct answer = 7236 × 56
Difference in answers = 470340 – 405216 = 65,124Question 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?
Solution
Length of cloth = 40 m = 40 × 100 cm = 4000 cmNumber of shirts can be stitched = 4000/215
Therefore, 18 shirts can be stitched and 130 cm (1 m 30 cm) cloth will remain.
Question 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?
Solution
The weight of one box = 4 kg 500 g = 4 × 1000 g + 500 g = 4500 g
Maximum load can be loaded in van = 800 kg = 800 × 1000 g = 800000 g
Number of boxes = 800000/4500
Therefore, 177 boxes can be loaded.
Question 11: The distance between the school and the house of a student’s house is 1 km 875 m. Every day she walks both ways. Find the total distance covered by her in six days.
Solution
Distance covered in six days = 3.750 × 6 = 22.500 kmTherefore, 22 km 500 m distance covered in six days.
Question 12: A vessel has 4 litres and 500 ml of curd. In how many glasses each of 25 ml capacity, can it be filled?
Solution
Capacity of curd in a vessel = 4 litres 500 ml = 4 × 1000 ml + 500 ml = 4500 ml
Capacity of one glass = 25 ml
Number of glasses can be filled = 4500/25
Therefore, 180 glasses can be filled by curd.
Exercise 1.3
Question 1: Estimate each of the following using general rule:
(a) 730 + 998
(b) 796 – 314
(c) 12,904 + 2,888
(d) 28,292 – 21,496
Solution
Question 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 – 48,365
Solution
Question 3: Estimate the following products using general rule:
(a) 578 × 161
(b) 5281 × 3491
(c) 1291 × 592
(d) 9250 × 29
Solution
(a) 578 × 161
578 round off to 600
161 round off to 200
The estimated product = 600 × 200 = 1,20,000
(b) 5281 × 3491
5281 round of to 5,000
3491 round off to 3,500
The estimated product = 5,000 × 3,500 = 1,75,00,000
(c) 1291 × 592
1291 round off to 1300
592 round off to 600
The estimated product = 1300 × 600 = 7,80,000
(d) 9250 × 29
9250 round off to 10,000
229 round off to 30
The estimated product = 10,000 × 30 = 3,00,000