VBA round(var,1) results in floating point error

I am using VBA to calculate and print a value to a worksheet. The calculated value is a "single" and I want to round it to one decimal place. For some reason, the "round" function rounds to the nearest decimal, but it still has what looks like floating point error on top of it. I can fix this manually, but I'd rather not have to every time and would like to understand what's actually going on.

I used the following code.

mysheet.Cells(row, ctotal).Value = Round(ttime, 1)

In one example, ttime is 2.183333 and the value that gets printed in the corresponding cell is 2.20000004768371. I would like it to print "2.2" in this case, without the rest of the nonsense thereafter. Any ideas?

I'd use WorksheetFunction.Round, since Round uses bankers rounding.

As a side effect, the return of WorksheetFunction.Round is a Double:

Dim ttime As Single
ttime = 2.183333
    
Debug.Print TypeName(Round(ttime, 1)) ' returns Single
Debug.Print TypeName(WorksheetFunction.Round(ttime, 1)) ' returns Double

If you do want bankers rounding, then:

Round(CDbl(ttime), 1)

You can control the decimals displayed by changing the cell's .NumberFormat:

mysheet.Cells(row, ctotal).NumberFormat = "0.0"