## NCERT Solutions For Class 6 Maths Knowing Our Numbers Exercise 1.3

**Exercise 1.3**

Ex 1.3 Class 6 Maths 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

Ex 1.3 Class 6 Maths 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

Ex 1.3 Class 6 Maths 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 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

Example 1.

382 x 1062

Solution:

382 x 1062 = 400 x 1000 = 4,00,000

Example 2.

6821 x 1291

Solution:

6821 x 1291 = 7000 x 1000 = 70,00,000

Example 3.

3858 x 9350

Solution:

3858 x 9350 = 4000 x 9000 = 3,60,00,000

Example 4.

3405 x 7502

Solution:

3405 x 7502 = 3000 x 8000 = 2,40,00,000

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