Haryana State Board HBSE 6th Class Maths Solutions Chapter 1 Knowing Our Numbers Ex 1.3 Textbook Exercise Questions and Answers.
Haryana Board 6th Class Maths Solutions Chapter 1 Knowing Our Numbers Exercise 1.3
Question 1.
Estimate :
(a) 730 + 998
(b) 796-314
(c) 12,904 + 2,888
(d) 28,292 – 21,496.
Solution:
(a) We find 998 > 730.
Round off to hundreds
Actual answer = 730 + 998 = 1728
1728 is rounded to 1700.
(b) To begin with, we round off to hundreds
Actual answer = 796 – 314 = 482
482 is rounded to 500.
(c) We find 12,904 > 2,888
Round off to thousands
12,904 is rounded to 13,000
+2,888 is rounded to 3,000
∴ Estimated sum = 16,000
Actual answer = 12,904 + 2,888 = 15,792
(d) To begin with, we round off to thousands
28,292 is rounded to 28,000
-21,496 is rouned to 21,000
∴ Estimated difference = 7,000
Actual answer = 28,292 – 21496
= 6,796
Question 2.
Give a rough estimate (by round 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 more of such examples.
Solution:
To begin with, we round off to thousands.
439 rounds to 0
334 rounds to 0
and 4,317 rounds to 4,000
Rough estimated sum= 0 + 0 + 4,000
= 4,000
This is not a reasonable estimate.
Actual sum = 439 + 334 + 4,317 = 5,090.
To get a closer estimate, let us try rounding off each number to hundreds.
(b) To begin with, we round off to ten thousands.
Actual difference = 1,08,734 – 47,599 = 61135
To get a closer estimate, let us try rounding off each number to hundreds.
(c) To begin with, we round off to hundreds
Actual difference = 8,325 – 491 = 7,834
To get a closer estimate let us try rounding off each number to tens.
This is a better and more meaningful estimate.
(d) To begin with, we round off to ten thousands
Actual difference = 4,89,348 – 48,365
= 4,40,983
To get a closer estimate, let us try rounding off each number to thousands.
