give a rough estimate by rounding off to nearest hundred and also closer estimate by rounding off to nearest tens .
a) 439+334+4317
b)108734- 47599
Answers
Answer:
439 + 334 + 4,317
Rounding off 439 to the nearest hundreds, we get 400
Rounding off 334 to the nearest hundreds, we get 300
And, rounding off 4,317 to the nearest hundreds, we get 4,300
Therefore, 400 + 300 + 4,300 = 5,000
It means that answer is equal to 5,000 when we round off different terms to the nearest hundreds.
Rounding off 439 to the nearest tens, we get 440
Rounding off 334 to the nearest tens, we get 330
And, rounding off 4,317 to the nearest tens, we get 4,320
Therefore, 440 + 330 + 4,320 = 5,090
It means that answer is equal to 5,090 when we round off different terms to the nearest tens.
Solution (b)
1,08,734 – 47,599
Rounding off 1,08,734 to the nearest hundreds, we get 1,08,700
And rounding off 47,599 to the nearest hundreds, we get 47,600
Therefore, 1,08,700-47,600=61,100
It means that answer is equal to 61,100 when we round off the terms to the nearest hundreds.
Rounding off 1,08,734 to the nearest tens, we get 1,08,730
And rounding off 47,599 to the nearest tens, we get 47,600
Therefore, 1,08,730-47,600=61,130
It means that answer is equal to 61,130 when we round off terms to the nearest tens.
Solution (c)
8,325 – 491
Rounding off 8,325 to the nearest hundreds, we get 8,300
And, rounding off 491 to the nearest hundreds, we get 500
Therefore, 8,300-500=7,800
It means that answer is equal to 7,800 when we round off terms to the nearest hundreds.
Rounding off 8,325 to the nearest tens, we get 8,330
And, rounding off 491 to the nearest tens, we get 490
Therefore, 8,330-490=7,840
It means that answer is equal to 7,840 when we round off terms to the nearest tens.
Solution (d)
4,89,348 – 48,365
Rounding off 4,89,348 to the nearest hundreds, we get 4,89,300
And, rounding off 48,365 to the nearest hundreds, we get 48,400
Therefore, 4,89,300-48,400=4,40,900
It means that answer is equal to 4,40,900 when we round off terms to the nearest hundreds.
Rounding off 4,89,348 to the nearest tens, we get 4,89,350
And, rounding off 48,365 to the nearest tens, we get 48,370
Therefore, 4,89,350-48,370=4,40,980
It means that answer is equal to 4,40,980 when we round off terms to the nearest tens.
Step-by-step explanation:
(a) 439 + 334 + 4317
Rounding off to nearest hundreds
439 + 334 + 4317 = 400 + 300 + 4300
= 5000
Rounding off to nearest tens
439 + 334 + 4317 = 440 + 330 + 4320
= 5090
(b) 108734 – 47599
Rounding off to nearest hundreds
108734 – 47599 = 108700 – 47600
= 61100
Rounding off to nearest tens
108734 – 47599 = 108730 – 47600
= 61130
(c) 8325 – 491
Rounding off to nearest hundreds
8325 – 491 = 8300 – 500
= 7800
Rounding off to nearest tens
8325 – 491 = 8330 – 490
= 7840
(d) 489348 – 48365
Rounding off to nearest hundreds
489348 – 48365 = 489300 – 48400
= 440900
Rounding off to nearest tens
489348 – 48365 = 489350 – 48370
= 440980
Four more examples are as follows
(i) 4853 + 662
Rounding off to nearest hundreds
4853 + 662 = 4800 + 700
= 5500
Rounding off to nearest tens
4853 + 662 = 4850 + 660
= 5510
(ii) 775 – 390
Rounding off to nearest hundreds
775 – 390 = 800 – 400
= 400
Rounding off to nearest tens
775 – 390 = 780 – 400
= 380
(iii) 6375 – 2875
Rounding off to nearest hundreds
6375 – 2875 = 6400 – 2900
= 3500
Rounding off to nearest tens
6375 – 2875 = 6380 – 2880
= 3500
(iv) 8246 – 6312
Rounding off to nearest hundreds
8246 – 6312 = 8200 – 6300
= 1900
Rounding off to nearest tens
8246 – 6312 = 8240 – 6310
= 1930