**Class 6 Mathematics Chapter 1 |**

Knowing Our Numbers | Exercise 1.3

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

**Answer: **

**(a)** 796 round off to 700

998 round off to 1000

Estimated sum= 1700

**(b)**796 round off to 800

314 round off to 300

Estimated difference= 800-300 = 500

**(c)** 12904 round off to 13000

2,888 round off to 3000

Estimated sum =13000+3000= 16000

**(d)** 28292 round off to 28000

21496 round off to 21000

Estimated difference=28000-21000= 7000

**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

**Answer:**

**(a)** 439 round off to 400

334 round off to 300

4317 round off to 4300

Estimated sum = 5000

**(b)** 108734 round off to 108700

47599 round off to 47600

Estimated difference = 61100

**(c)** 8325 round off to 8300

491 round off to 500

Estimated difference = 7800

**(d)** 489348 round off to 489300

48365 round off to 48400

Estimated difference = 440900

**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

**Answer:**

(a) 578 round off to 600

161 round off to 200

The estimated product = 600 x 200 = 1,20,000

(b) 5281 round of to 5,000

3491 round off to 3,500

The estimated product = 5,000 x 3,500 = 1,75,00,000

(c)1291 round off to 1300

592 round off to 600

The estimated product = 1300 x 600 = 7,80,000

(d)9250 round off to 10,000

229 round off to 30

The estimated product = 10,000 x 30 = 3,00,000