How can I round a number to 2 significant figures

IN an Access report - Why can't I - or better still HOW CAN I - convert a
number in a field to show as - say - 2 significant figures - the ROUND()
function only does it to decimal places - Why can't I use the code that is
used in Excel i.e. =ROUND(A2,3-LEN(INT(A2))) to give me a figure with 2
significant figures !!! that is if A2 = 5492820 I get 5500000.

This is so important in my laboratory reporting program !
Many thanks
--
Glen
Simple Scientist aka Microbiologist
Brisbane
Australia

See:
http://allenbrowne.com/round.html#RoundNegativePlaces

The article provides a couple of alternatives: an alternative formula, or a
custom rounding function.

--
Allen Browne - Microsoft MVP. Perth, Western Australia
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.

"Glen in Australia" wrote in
message
...
IN an Access report - Why can't I - or better still HOW CAN I - convert a
number in a field to show as - say - 2 significant figures - the ROUND()
function only does it to decimal places - Why can't I use the code that is
used in Excel i.e. =ROUND(A2,3-LEN(INT(A2))) to give me a figure with 2
significant figures !!! that is if A2 = 5492820 I get 5500000.

This is so important in my laboratory reporting program !
Many thanks
--
Glen
Simple Scientist aka Microbiologist
Brisbane
Australia

Why can't you? Because Access isn't Excel.

How can you? Well, a brief Google turned this up:

Public Function FormatSigFig(Value As Double, SigFigs As Long) As String
Dim RoundedValue As Double
Dim Digits As Long
Digits = SigFigs - Int(Log(Abs(Value)) / Log(10)) - 1
FormatSigFig = Int(0.5 + Value * 10 ^ Digits) / 10 ^ Digits
End Function

Seems to work, although I haven't given it much of a test.

If you are ever inclined to use the Access Round function, you should be
aware that it does bankers' rounding, not arithmetical rounding.


"Glen in Australia" wrote in
message ...
IN an Access report - Why can't I - or better still HOW CAN I - convert a
number in a field to show as - say - 2 significant figures - the ROUND()
function only does it to decimal places - Why can't I use the code that is
used in Excel i.e. =ROUND(A2,3-LEN(INT(A2))) to give me a figure with 2
significant figures !!! that is if A2 = 5492820 I get 5500000.

This is so important in my laboratory reporting program !
Many thanks
--
Glen
Simple Scientist aka Microbiologist
Brisbane
Australia