# Free Ncert Class 6 Math Knowing Our Numbers Exercise 1.3

Knowing Our Numbers Class 6 Ex. 1.3

## Knowing Our Numbers Ncert Class 6 Math Solution Ex.-1.3.

Knowing Our Numbers Exercise 1.1

Knowing Our Numbers Exercise 1.2

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.

Solution 1:-
(a) 730 + 998

730 Rounding off to = 700   (nearest to hundreds)
998 Rounding off to = 1,000 (nearest to hundreds)
So,           730 + 998 = 700 + 1000 = 1700

(b) 796 – 314

796 Rounding off to = 800 (nearest to hundreds)
314 Rounding off to = 300 (nearest to hundreds)
So,            796 – 314 = 800 – 300 = 500

(c) 12,904 + 2,888

12,904 Rounding off to  = 13000 (nearest to thousands)
2,888   Rounding off to = 3000 (nearest to thousands)
So,        12,904 + 2,888 = 13000 + 3000 = 16000

(d) 28,292 – 21,496

28,292 Rounding off to = 28,000 (nearest to thousands)
21,496 Rounding off to = 21,000 (nearest to thousands)
So,       28,292 – 21,496 = 28,000 – 21,000 = 7,000

Example 1:  1201 + 2356 = 1200 + 2400 = 3600
Example 2:  3863 + 6542 = 4000 + 7000 = 11,000
Example 3:  8762 – 3664 = 9,000 – 4,000 = 5,000
Example 4:  4548 – 2956 = 5,000 – 3,000 = 2,000
Example 5:  1937 + 3158 = 2000 + 3,000 = 5,000
Example 6:  3285 – 1689 = 3000 – 2000 = 1,000
Example 7:  8745 + 6223 = 9000 + 6000 = 15,000
Example 8:  1048 – 1038 = 1000 – 1000 = 0
Example 9:  6362 + 5803 = 6,000 + 6,000 = 12,000
Example 10: 9864 – 6358 = 10,000 – 6000 = 4,000

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 2:-

(a) 439 + 334 + 4,317

•  The rough estimate (by rounding off to nearest hundreds)
439 + 334 + 4,317 = 400 + 300 + 4300 = 5,00
•  The closer estimate (by rounding off to nearest tens)
439 + 334 + 4317 = 440 + 330 + 4320 = 5090.

(b) 1,08,734 – 47,599

•  The rough estimate (By rounding off to nearest hundreds)
1,08,734 – 47,599 = 1,08,700 – 47,600 = 61,100
•  The closer estimate (By rounding off to nearest tens)
1,08,734 – 47,599 = 1,08,730 – 47,600 = 61,130.

(c) 8325 – 491

• The rough estimate (by rounding off to nearest hundreds)
8325 – 491 = 8300 – 500 = 7800
• The closer estimate (by rounding off to nearest tens)
8325 – 491 = 8330 – 490 = 7840.

(d) 4,89,348 – 48,365

• The rough estimate (by rounding off to nearest hundreds)
4,89,348 – 48,365 = 4,89,300 – 48,400 = 4,40,900
• The closer estimate (by rounding off to nearest tens)
4,89,348 – 48,365 = 4,89,350 – 48,370 = 4,40,980

Example 1: 383 + 561
Solution 1:
(i) The rough estimate (by Rounding off to nearest hundreds)
383 + 561 = 400 + 600 = 1,000
(ii) The closer estimate (by Rounding off to nearest tens)
383 + 561 = 380 + 560 = 940

Example 2: 8766 – 3819
Solution 2:
(i) The rough estimate (by rounding off to nearest hundreds)
8766 – 3819 = 8800 – 3900 = 4900
(ii) The closer estimate (by rounding off to nearest tens)
8766 – 3819 = 8770 – 3820 = 4950

Example 3: 6654 – 8266
Solution 3:-
(i) The rough estimate (by rounding off to nearest hundreds)
6654 + 8266 = 6700 + 8300 = 15,000
(ii) The closer estimate (by rounding off to nearest tens)
6654 + 8266 = 6650 + 8270 = 14920

Example 4: 3827 – 1261
Solution 4:-
(i) The rough estimate (by rounding off to nearest hundreds)
3827 – 1261 = 3800 – 1300 = 2500
(ii) The closer estimate (by rounding off to nearest tens)
3827 – 1261 = 3830 – 1260 = 2570 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
Make four more such examples.

Solution:
(a) 578 x 161 = 600 x 200 = 1,20,000
(b) 5281 x 3491 = 5000 x 3500 = 1,75,00,000
(c) 1291 x 592 = 1300 x 600 = 7,80,000
(d) 9250 x 29 = 9000 x 30 = 2,70,000

Example 1. 384 x 1026
Solution 1:
384 x 1026 = 400 x 1000 = 4,00,000

Example 2. 6812 x 1191
Solution 2:
6812 x 1191 = 7000 x 1000 = 70,00,000

Example 3. 3888 x 9150
Solution 3:-
3888 x 9150 = 4000 x 9000 = 3,60,00,000

Example 4. 3005 x 7520
Solution 4:-
3005 x 7520 = 3000 x 8000 = 2,40,00,000

Ncert Solution for Class 6 Chapter 1 Knowing Our Number

Knowing Our Numbers

Knowing Our Numbers

Knowing Our Numbers

Knowing Our Numbers