NCERT Class 6 Maths Chapter 1 Knowing our Numbers Exercise 1.3


Chapter 1 Knowing our Numbers 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
Make ten more such examples of addition, subtraction and estimation of their outcome.
Answer:

a)
Round off to hundreds
730 rounds off to 700
998 rounds off to 1000
= 700 + 1000 = 1700

b)
Round off to hundreds
796 rounds off to 800
314 rounds off to 300
= 800 - 300 = 500

c)
Round off to thousands
12904 rounds off to 13000
2888 rounds off to 3000
= 13000 + 3000 = 16000

d)
Round off to thousands
28292 round off to 28000
21496 round off to 21000
= 28000 - 21000 = 7000

Ten examples of such addition and subtraction are
i) 460 + 290
Round off to hundreds
460 round off to 500
290 round off to 300
= 500 + 300 = 800

ii) 3999 + 5100
Round off to thousands
3999 round off to 4000
5100 round off to 5000
= 4000 + 5000 = 9000

iii) 611 - 455
Round off to hundreds
611 round off to 600
455 round off to 500
= 600 - 500 = 100

iv) 5440 - 2972
Round off to thousands
5440 round off to 5000
2972 round off to 3000
= 5000 - 3000 = 2000

v) 2091 + 9845
Round off to thousands
2091 round off to 2000
9845 round off to 10000
= 2000 + 10000 = 12000

vi) 1990 - 1292
Round off to thousands
1990 round off to 2000
1292 round off to 1300
= 2000 - 1300 = 700

vii) 9100 + 5750
Round off to thousands
9100 round off to 9000
5750 round off to 6000
= 9000 + 6000 = 15000

viii) 6400 + 4900
Round off to thousands
6400 round off to 6000
4900 round off to 5000
= 6000 + 5000 = 11000

ix) 3731 - 1300
Round off to thousands
3731 round off to 4000
1300 round off to 1000
= 4000 - 1000 = 3000

x) 6885 - 4356
Round off to thousands
6885 round off to 7000
4356 round off to 4000
= 7000 - 4000 = 3000

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) 8325 - 491
d) 4,89,348 - 48,365
Make four more such examples.
Answer:

a)
Rounding off to nearest hundreds
439 round off to 400
334 round off to 300
4317 round off to 4300
= 400 + 300 + 4300 = 5000
Rounding off to nearest tens
439 round off to 440
334 round off to 330
4317 round off to 4320
= 440 + 330 + 4320 = 5090

b)
Rounding off to nearest hundreds
1,08,734 round off to 108700
47,599 round off to 47600
= 108700 - 47600 = 61100
Rounding off to nearest tens
1,08,734 round off to 108730
47,599 round off to 47600
= 108730 - 47600 = 61130

c)
Rounding off to nearest hundreds
8325 round off to 8300
491 round off to 500
= 8300 - 500 = 7800
Rounding off to nearest tens
8325 round off to 8330
491 round off to 490
= 8330 - 490 = 7840

d)
Rounding off to nearest hundreds
489348 round off to 489300
48365 round off to 48400
= 489300 - 48400 = 440900
Rounding off to nearest tens
489348 round off to 489350
48365 round off to 48370
= 489350 - 48370 = 440980

Four examples of such are
i) 4899 + 662
Rounding off to nearest hundreds
4899 round off to 4900
662 round off to 700
= 4900 + 700 = 5600
Rounding off to nearest tens
4899 round off to 4900
662 round off to 660
= 4900 + 660 = 5560

ii) 770 - 310
Rounding off to nearest hundreds
770 round off to 800
310 round off to 300
= 800 - 300 = 400
Rounding off to nearest tens
770 round off to 770
310 round off to 310
= 770 - 310 = 460

iii) 63740 - 28759
Rounding off to nearest hundreds
63740 round off to 63700
28759 round off to 28600
= 63700 – 28600 = 35100
Rounding off to nearest tens
63740 round off to 63740
28759 round off to 28760
= 63740 - 28760 = 34980

iv) 8972 + 3548
Rounding off to nearest hundreds
8972 round off to 9000
3548 round off to 3500
= 9000 + 3500 = 12500
Rounding off to nearest tens
8972 round off to 8970
3548 round off to 3550
= 8970 + 3550 = 12520

Question 3: Estimate the following products using general rule:
a) 578 × 161
b) 5281 × 3491
c) 1291 × 592
d) 9250 × 29
Make four more such examples.
Answer:

a)
Rounding off by general rule
578 round off to 600
161 round off to 200
600 × 200 = 120000

b)
Rounding off by general rule
5281 round off to 5000
3491 round off to 3500
= 5000 × 3500 = 17500000

c)
Rounding off by general rule
1291 round off to 1300
592 round off to 600
= 1300 × 600 = 780000

d)
Rounding off by general rule
9250 round off to 9000
29 round off 30
= 9000 × 30 = 270000

Four examples of such are
i) 5340 × 89
Rounding off by general rule
5340 round off to 5000
89 round off 90
= 5000 × 90 = 450000

ii) 998 × 115
Rounding off by general rule
998 round off to 1000
115 round off to 120
= 1000 × 120 = 120000

iii) 4888 × 654
Rounding off by general rule
4888 round off to 4900
654 round off to 700
= 4900 × 700 = 3430000

iv) 382 x 1062
Rounding off by general rule
382 round off to 400
1062 round off to 1000
= 400 x 1000 = 400000

No comments:

Post a Comment

Also read!

Click on any of the below text for additional links:

Class 6

Class 6 Computer Kips Solutions
Class 6 Gul Mohar English Solutions
→ Class 6 Map Pointing Solutions
Class 6 NCERT Civics Solutions
Class 6 NCERT Geography Solutions
Class 6 NCERT History Solutions
Class 6 NCERT Maths Solutions
Class 6 NCERT Science Solutions

Class 7

Class 7 Computer Kips Solutions
Class 7 Gul Mohar English Solutions
English Grammar Class 7
English Writing Skills Class 7
Class 7 Map Pointing Solutions
Class 7 NCERT Civics Solutions
Class 7 NCERT Civics Notes
Class 7 NCERT Civics Extra Questions
Class 7 NCERT Geography Solutions
Class 7 NCERT Geography Notes
Class 7 NCERT Geography Extra Questions
Class 7 NCERT History Solutions
Class 7 NCERT History Notes
Class 7 NCERT History Extra Questions
Class 7 NCERT Maths Solutions
Class 7 NCERT Science Solutions
Class 7 NCERT Science Notes
Class 7 NCERT Science Extra Questions

Class 8

Class 8 Kips Artificial Intelligence Solutions
Class 8 Gul Mohar English Solutions
English Grammar Class 8
English Writing Skills Class 8
Class 8 Map Pointing Solutions
Class 8 NCERT Civics Solutions
Class 8 NCERT Civics Notes
Class 8 NCERT Civics Extra Questions
Class 8 NCERT Geography Solutions
Class 8 NCERT Geography Notes
Class 8 NCERT Geography Extra Questions
Class 8 NCERT History Solutions
Class 8 NCERT History Notes
Class 8 NCERT History Extra Questions
Class 8 NCERT Maths Solutions
Class 8 NCERT Science Solutions
Class 8 NCERT Science Notes
Class 8 NCERT Science Extra Questions
Class 8 NCERT Science Exemplar
Class 8 NCERT Science MCQs

Class 9

Class 9 Kips Artificial Intelligence Solutions
Class 9 Map Pointing Solutions
Class 9 NCERT Civics Solutions
Class 9 NCERT Geography Solutions
Class 9 NCERT History Solutions
Class 9 NCERT Maths Solutions
Class 9 NCERT Science Solutions

Class 10

Class 10 Kips Artificial Intelligence Solutions
Class 10 NCERT English Solutions
→ Class 10 Map Pointing Solutions
Class 10 NCERT Civics Solutions
Class 10 NCERT Civics Notes
Class 10 NCERT Civics Extra Questions
Class 10 NCERT Geography Solutions
Class 10 NCERT Geography Notes
Class 10 NCERT Geography Extra Questions
Class 10 NCERT History Solutions
→ Class 10 NCERT History Notes
Class 10 NCERT History Extra Questions
Class 10 NCERT Maths Solutions
Class 10 NCERT Science Solutions
Class 10 NCERT Science Notes
Class 10 NCERT Science Extra Questions

Computer Languages

Python Basics

Extra Activities

Extra Activities

Extra Knowledge

Extra Information
General Knowledge
Historical Places in India
Latest technology
Physical Sciences
Facts

• Mathematics quick links
Mathematical Terms
Maths Tricks

Home Top