PS....

"pfdubz" wrote:
When I calculate ROUND(HR*HW,2) which I will label "A" and then multiply
that by the BLR using ROUND( A*BLR,2) I get 8104.93. However, when I
calculate ROUND(HR*BLR,2) which I will label "B" and then multiply that by
the HW using ROUND(B*HW,2), I get 8105.40.
[....]
Unfortunatley, I have use the two different methods in two different
places of a report.

If you are asking "which is right?", you should do whichever rounding
matches intermediate numbers in your report, if you show only "A" or "B",
but not both.

If you do not show "A" and "B" anywhere in the report, you should compute

=round(HR*HW*BLR,2)

On the other hand, if you show both "A" and "B" in the report, I would use
the above formula in both places to compute the final charge, and I would
add a footnoote to explain that rounding can affect the calculation. That
is a common accounting practice.

However, if the practices of your industry require that you perform the
computations exactly as you have done, you need to go to accounting experts
familiar with your industry to resolve the conflict. I seriously doubt that
this step is necessary.


----- original message -----

"JoeU2004" wrote in message
...
Do the math! Rounding is not a commutative operation.


When I calculate ROUND(HR*HW,2) which I will label "A"
and then multiply
that by the BLR using ROUND( A*BLR,2) I get 8104.93

The second ROUND is multiplying 5367.50 times 1.51.


when I calculate ROUND(HR*BLR,2) which I will label "B"
and then multiply that by
the HW using ROUND(B*HW,2), I get 8105.40.

The second ROUND is multiplying 85.32 times 95.

The difference is large because in the first case, any rounding error is
small relative to the unrounded result (in fact, there is no error!),
whereas in the second case, the rounding error is larger relative to the
unround result.


----- original message -----

"pfdubz" wrote in message
...
I have an interesting conundrum with the Excel round function.
I have three numbers - Hourly Rate (HR), Hours Worked (HW) and Burdened
Labor Rate (BLR). HR =56.50, Hw = 95, and BLR = 1.51.
When I calculate ROUND(HR*HW,2) which I will label "A" and then multiply
that by the BLR using ROUND( A*BLR,2) I get 8104.93. However, when I
calculate ROUND(HR*BLR,2) which I will label "B" and then multiply that
by
the HW using ROUND(B*HW,2), I get 8105.40.
Why is that and how do I get equal numbers using the two methods.
Unfortunatley, I have use the two different methods in two different
places
of a report.
--
Paul