Class-6 Subject-Maths Chapter-1 Exercise1.3 Knowing our Numbers

 

EVENTS CONVENT HIGH SCHOOL
10/08/2021          CLASS-6         SESSION2021-22(SLOT-1)
Maths
Chapter-1
Knowing our Numbers
______________________________________

QUESTION-1 EXPLANATION

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

Make ten more such examples of addition, subtraction and estimation of their outcome.

Solution:

(a) 730 + 998

Rounding off 730 nearest to hundreds = 700

Rounding off 998 nearest to hundreds = 1,000

∴ 730 + 998 = 700 + 1000 = 1700

 

(b) 796 – 314

Rounding off 796 nearest to hundreds = 800

Rounding off 314 nearest to hundreds = 300

∴ 796 – 314 = 800 – 300 = 500

 

(c) 12,904 + 2,888

Rounding off 12,904 nearest to thousands = 13000

Rounding off 2888 nearest to thousands = 3000

∴ 12,904 + 2,888 = 13000 + 3000 = 16000

 

(d) 28,292 – 21,496

Rounding off 28,292 nearest to thousands = 28,000

Rounding off 21,496 nearest to thousands = 21,000

∴ 28,292 – 21,496 = 28,000 – 21,000 = 7,000

 

Example 1: 1210 + 2365 = 1200 + 2400 = 3600

Example 2: 3853 + 6524 = 4000 + 7000 = 11,000

Example 3: 8752 – 3654 = 9,000 – 4,000 = 5,000

Example 4: 4538 – 2965 = 5,000 – 3,000 = 2,000

Example 5: 1927 + 3185 = 2000 + 3,000 = 5,000

Example 6: 3258 – 1698 = 3000 – 2000 = 1,000

Example 7: 8735 + 6232 = 9000 + 6000 = 15,000

Example 8: 1038 – 1028 = 1000 – 1000 = 0

Example 9: 6352 + 5830 = 6,000 + 6,000 = 12,000

Example 10: 9854 – 6385 = 10,000 – 6000 = 4,000

QUESTION-2 EXPLANATION

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 + 4,317

(b) 1,08,734-47,599

(c) 8,325-491

(d) 4,89,348-48,365

Make four such examples:

Solution:

(a)439 + 334 + 4,317

(i) Rough estimate (Rounding off to nearest hundreds)

439 + 334 + 4,317 = 400 + 300 + 4300 = 5,000

(ii) Closer estimate (Rounding off to nearest tens)

439 + 334 + 4317 = 440 + 330 + 4320 = 5090.

 

(b) 1,08,734 – 47,599

(i) Rough estimate (Rounding off to nearest hundreds)

1,08,734 – 47,599 = 1,08,700 – 47,600 = 61,100

(ii) Closer estimate (Rounding off to nearest tens)

1,08,734 – 47,599 = 1,08,730 – 47,600 = 61,130.

 

(c) 8325 – 491

(i) Rough estimate (Rounding off to nearest hundreds)

8325 – 491 = 8300 – 500 = 7800

(ii) Closer estimate (Rounding off to nearest tens)

8325 – 491 = 8330 – 490 = 7840.

 

(d) 4,89,348 – 48,365

(i) Rough estimate (Rounding off to nearest hundreds)

4,89,348 – 48,365 = 4,89,300 – 48,400 = 4,40,900

(ii) Closer estimate (Rounding off to nearest tens)

4,89,348 – 48,365 = 4,89,350 – 48,370 = 4,40,980

 

Example 1:384 + 562

Solution:(i) Rough estimate (Rounding off to nearest hundreds)

384 + 562 = 400 + 600

= 1,000

(ii) Closer estimate (Rounding off to nearest tens)

384 + 562 = 380 + 560

= 940

 

Example 2:8765 – 3820

Solution:(i) Rough estimate (Rounding off to nearest hundreds)

8765 – 3820 = 8800 – 3900

= 4900

(ii) Closer estimate (Rounding off to nearest tens)

8765 – 3820 = 8770 – 3820

= 4950

 

Example 3:6653 – 8265

Solution:(i) Rough estimate (Rounding off to nearest hundreds)

6653 + 8265 = 6700 + 8300

= 15,000

(ii) Closer estimate (Rounding off to nearest tens)

6653 + 8265 = 6650 + 8270

= 14920

 

Example 4:3826 – 1262

Solution:(i) Rough estimate (Rounding off to nearest hundreds)

3826 – 1262 = 3800 – 1300

= 2500

(ii) Closer estimate (Rounding off to nearest tens)

3826 – 1262 = 3830 – 1260

= 2570

QUESTION-3 EXPLANATION

Question 3.Estimate the following products using general rule:

(a) 578 x 161

(b)5281 x 3491

(c) 1291 x 592

(d) 9250 x 29

Solution:

(a) 578 x 161 = 600 x 200 = 1,20,000

(b) 5281 x 3491 = 5000 x 3000 = 1,50,00,000

(c) 1291 x 592 = 1300 x 600 = 7,80,000

(d) 9250 x 29 = 9000 x 30 = 2,70,000

 

Class-6 Subject-Maths Chapter-1 Exercise1.2 Knowing our Numbers

 EVENTS CONVENT HIGH SCHOOL
05/08/2021          CLASS-6                 SESSION2021-22(SLOT-1)
MATHS
CHAPTER-1
KNOWING OUR NUMBERS(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:

Number of tickets sold on the first day = 1094

Number of tickets sold on the second day = 1812

Number of tickets sold on the third day = 2050

Number of tickets sold on the final day = 2751

∴ Total number of tickets sold on all the four days = 1094 + 1812 + 2050 + 2751 = 7,707.

 

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:

Shekhar has so far scored 6980 runs

He wishes to complete 10,000 runs.

Therefore total number of runs needed by him = 10,000 – 6980 = 3020 runs

 

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:

Number of votes secured by the successful candidate = 5,77,500

Number of votes secured by his nearest rival = 3,48,700

Therefore, margin of votes to win the election = 5,77,500 – 3,48,700 = 2,28,800

 

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:

Books sold in first week of June worth ₹2,85,891

Books sold in second week of the month worth ₹4,00,768

Therefore, total sale of books in the two weeks together

= ₹2,85,891 + ₹4,00,768 = ₹6,86,659

In the second week of the month, the sale of books was greater.

Difference of the sale of books

= ₹4,00,768 – ₹2,85,891 = ₹1,14,877

Hence, in second week of june, the sale of books was more by ₹1,14,877.

Class-6 Subject-Maths Chapter-1 Slot-1 Knowing Our Numbers (Ex1.1)

 

EVENTS CONVENT HIGH SCHOOL
31/07/2021          CLASS-6         SESSION2021-22(SLOT-1)
Maths
Chapter-1
Knowing our Numbers
______________________________________

Knowing our Numbers Chapter Explanation

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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) 1 lakh = ten ten thousand.

(b) 1 million = ten hundred thousand.

(c) 1 crore = ten ten lakh

(d) 1 crore = ten million

(e) 1 million = ten lakh

 

Question 2.Place commas correctly and write the numerals:

(a) Seventy-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.

Solution:

(a) 73,75,307

(b) 9,05,00,041

(c) 7,52,21,302

(d) 5,84,23,202

(e) 23,30,010.

 

Question 3.Insert commas suitably 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 seventy-five lakh ninety-five thousand seven hundred sixty- two)

(b) 85,46,283 (Eighty-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 one)

 

Question 4.Insert commas suitably and write the names according to International System of Numeration:

(a) 78921092

(b) 7452283

(c) 99985102

(d) 48049831

Solution:

(a) 78,921,092 (Seventy-eight million nine hundred twenty-one thousand ninety-two)

(b) 7,452,283 (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-one)