I was using this in If activity
in_CompareDT.AsEnumerable().Sum(Function(row) cdbl(row.Item(in_BalanceColumnName))) = 0
and it was working perfectly with decimals. But today it got false even if it was true. The result was -7.45058059692383E-09
Then I put the rows in a for each row activity and sum them one by one to see if a value comes in incorrect format. (sum = sum + cdbl(row.item(0))). It sums -74578741.07 and 79970356, gives the result 5391614.92999999.
After that I simply used 3 assigns which num1 = 1, num2 = -0.07 and sum = num1 + num2, the result was the image above.
For this I will use rounding but I wonder why it only happens while extracting 0.07.