Android Question Rounding Numbers: Round2 or Numberformat2

This rule provides more accuracy and is sometimes referred to as the 'Banker's Rule'. When the first digit dropped is 5 and there are no digits following or the digits following are zeros, make the preceding digit even (i.e. round off to the nearest even digit). E.g., 2.315 and 2.325 are both 2.32 when rounded off to the nearest hundredth. Note: The rationale for the third rule is that approximately half of the time the number will be rounded up and the other half of the time it will be rounded down.

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Sub Globals
   
Dim m1,m2 ,m3 As Double
Dim n As Int = 100000
End Sub

Sub Activity_Create(FirstTime As Boolean)
Dim x, y, z As Double
For i = 1 To n
    x = Rnd(0,1000) /1000
    y = Round2(x,2)
    z = NumberFormat(x,1,2)
'    Log(x & " " & y & " " & z)
    m1 = m1 + x
    m2 = m2 + y
    m3 = m3 + z
Next
Log("n = " & n)
m1 = m1/n
m2 = m2/n
m3 = m3/n
Log("true =  " & m1 )
Log("round=  " & m2)
Log("format= " &  m3)
Log("round_dif  = " & NumberFormat((m2-m1),1,5))
Log("format_dif = " & NumberFormat((m3-m1),1,5))
End Sub

** Activity (main) Resume **
** Activity (main) Create, isFirst = true **
n = 10000
true = 0.5028684000000027
round= 0.503301000000001
format= 0.5028590000000008
round_dif = 0.00043
format_dif = -0.00001
** Activity (main) Resume **
** Activity (main) Create, isFirst = true **
n = 100000
true = 0.4999440600000005
round= 0.5004085999999968
format= 0.49993360000000014
round_dif = 0.00046
format_dif = -0.00001

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