Almost 30 children are there in the house 10.
When the exact value is
unknown we can actually give
the approximate number or the
closer value
While rounding off numbers to nearest tens, the
ones digit is rounded off to the nearest ten.
Example: 23 will be rounded off to 20
Because 23 is nearer to 20.
26 will be rounded off to 30
Because 26 is nearer to 30.
Halfway number
The halfway numbers are rounded off to
the higher tens.
While rounding off numbers to nearest hundreds, the
ones digit and tens digit are rounded off to the nearest
hundreds.
Example: 120 will be rounded off to 100
Because 120 is nearer to 100.
180 will be rounded off to 200
Because 180 is nearer to 200
The halfway numbers are rounded off to the
higher hundreds.
While rounding off numbers to nearest thousands, the
ones, tens and hundreds digit are rounded off to the
nearest thousands.
Example: 1400 will be rounded off to 1000
Because 1400 is nearer to 1000.
1600 will be rounded off to 2000
Because 1600 is nearer to 2000.
The halfway numbers are rounded off to the higher
thousands.
How to round off numbers to the nearest tens?
Numbers lower than the halfway numbers are
rounded off to the lower tens.
Example:
63 will be rounded off to 60
Numbers greater than the halfway numbers are
rounded off to the higher tens.
Example: 67 will be rounded off to 70
How to round off numbers to the nearest
hundreds?
 Numbers greater than the halfway numbers are
rounded off to the higher hundreds.
Example:
263 will be rounded off to 300 263
200 210 220 230 240 250 260 270 280 300290
Numbers lower than the halfway numbers are
rounded off to the lower hundreds.
Example:
232 will be rounded off to 200
200 210 220 230 240 250 260 270 280 300290
232
How to round off numbers to the nearest
thousands?
 Numbers greater than the halfway numbers are
rounded off to the higher thousands.
Example:
4603 will be rounded off to 5000
4603
4000 4100 4200 4300 4400 4500 4600 4700 4800 50004900
4000 4100 4200 4300 4400 4500 4600 4700 4800 50004900
Numbers lower than the halfway numbers are
rounded off to the lower thousands.
Example:
4332 will be rounded off to 4000
4332
How to round off halfway numbers?
Halfway numbers are rounded off to the higher
tens, hundreds or thousands.
Assignment:
Round off the following numbers:
a. nearest tens b. nearest hundreds c. nearest thousands
1.1 362 a. b. c.
2.3 837 a. b. c.
3.5 742 a. b. c.
4.6 424 a. b. c.
5.9 654 a. b. c.
Roundingoffnumbers

Roundingoffnumbers

  • 3.
    Almost 30 childrenare there in the house 10.
  • 4.
    When the exactvalue is unknown we can actually give the approximate number or the closer value
  • 5.
    While rounding offnumbers to nearest tens, the ones digit is rounded off to the nearest ten. Example: 23 will be rounded off to 20 Because 23 is nearer to 20. 26 will be rounded off to 30 Because 26 is nearer to 30.
  • 6.
    Halfway number The halfwaynumbers are rounded off to the higher tens.
  • 7.
    While rounding offnumbers to nearest hundreds, the ones digit and tens digit are rounded off to the nearest hundreds. Example: 120 will be rounded off to 100 Because 120 is nearer to 100. 180 will be rounded off to 200 Because 180 is nearer to 200
  • 8.
    The halfway numbersare rounded off to the higher hundreds.
  • 9.
    While rounding offnumbers to nearest thousands, the ones, tens and hundreds digit are rounded off to the nearest thousands. Example: 1400 will be rounded off to 1000 Because 1400 is nearer to 1000. 1600 will be rounded off to 2000 Because 1600 is nearer to 2000.
  • 10.
    The halfway numbersare rounded off to the higher thousands.
  • 11.
    How to roundoff numbers to the nearest tens? Numbers lower than the halfway numbers are rounded off to the lower tens. Example: 63 will be rounded off to 60 Numbers greater than the halfway numbers are rounded off to the higher tens. Example: 67 will be rounded off to 70
  • 12.
    How to roundoff numbers to the nearest hundreds?  Numbers greater than the halfway numbers are rounded off to the higher hundreds. Example: 263 will be rounded off to 300 263 200 210 220 230 240 250 260 270 280 300290
  • 13.
    Numbers lower thanthe halfway numbers are rounded off to the lower hundreds. Example: 232 will be rounded off to 200 200 210 220 230 240 250 260 270 280 300290 232
  • 14.
    How to roundoff numbers to the nearest thousands?  Numbers greater than the halfway numbers are rounded off to the higher thousands. Example: 4603 will be rounded off to 5000 4603 4000 4100 4200 4300 4400 4500 4600 4700 4800 50004900
  • 15.
    4000 4100 42004300 4400 4500 4600 4700 4800 50004900 Numbers lower than the halfway numbers are rounded off to the lower thousands. Example: 4332 will be rounded off to 4000 4332
  • 16.
    How to roundoff halfway numbers? Halfway numbers are rounded off to the higher tens, hundreds or thousands.
  • 17.
    Assignment: Round off thefollowing numbers: a. nearest tens b. nearest hundreds c. nearest thousands 1.1 362 a. b. c. 2.3 837 a. b. c. 3.5 742 a. b. c. 4.6 424 a. b. c. 5.9 654 a. b. c.