Rounding Difference

Question

In my attached sample file you can see I am trying to calculate the tax amount by multiple rate and tax base amount, then use it to minus output tax. I use the round to keep 2 decimals but why I still have the difference for line 2? Is this a bug?

RateOutput taxTax base amountTax AmountDifferenceround valueround difference20(88.32)(441.60)(88.32)0.00(88.32)(0.00)20(1,094.1000000000)(5,470.52)(1,094.1040000000000)(0.0040000000001)(1,094.1000000000)(0.00000000000023)

rounding issue.yxmd

philipmannering · Answer

☝️ What @Clifford_Coon said. Computers aren't good at decimals, they're good at binary. Use a Fixed Decimal (Precision ≈ 19 and Scale = 2) to only show the first two decimal places.

Clifford_Coon · Answer

Hi,

One simple approach it to change your types from double to FixedDecimal   (precision 19 Scale 2) for the columns you are creating in the foumula tool.

When I idd, i get this:

Rate Output tax     Tax base amount Tax Amount Difference round value round difference
20     -88.32            -441.6                 -88.32           0.00         -88.32        -0.00
20     -1094.1           -5470.52            -1094.10     -0.00         -1094.10     -0.00