Microsoft KB Archive/185479

= How To Display a Number as a Fraction =

Article ID: 185479

Article Last Modified on 11/23/2006

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APPLIES TO


 * Microsoft Visual Basic for Applications 5.0

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This article was previously published under Q185479



SUMMARY
This article provides three routines to convert a decimal fraction to the form "a b/c".



MORE INFORMATION
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In many instances, it is useful to be able to output a decimal value as a fraction in the form "a/b" or "a b/c". This article provides three routines that perform that function. Function       Description ---

Frac2Num       Returns a normalized fraction with the denominator in the range of 2..8.

Frac2NumA      Returns a non-normalized fraction with the denominator you specify.

Frac2NumB      Returns a normalized fraction based on a denominator you specify. A normalized fraction contains the smallest possible denominator. The GCF function (Greatest Common Factor) is used in the normalization process.

Example
Non-normalized : 4/6

Normalized : 2/3

Sample Code
  Create a new project and add the following code to a Module: Function Num2Frac (ByVal X As Double) As String Dim Fixed As Double, Temp As String X = Abs(X) Fixed = Int(X) If Fixed > 0 Then Temp = CStr(Fixed) End If       Select Case X - Fixed Case .1 To .145 Temp = Temp + " 1/8" Case .145 To .182 Temp = Temp + " 1/6" Case .182 To .225 Temp = Temp + " 1/5" Case .225 To .29 Temp = Temp + " 1/4" Case .29 To .35 Temp = Temp + " 1/3" Case .35 To .3875 Temp = Temp + " 3/8" Case .3875 To .45 Temp = Temp + " 2/5" Case .45 To .55 Temp = Temp + " 1/2" Case .55 To .6175 Temp = Temp + " 3/5" Case .6175 To .64 Temp = Temp + " 5/8" Case .64 To .7 Temp = Temp + " 2/3" Case .7 To .775 Temp = Temp + " 3/4" Case .775 To .8375 Temp = Temp + " 4/5" Case .8735 To .91 Temp = Temp + " 7/8" Case Is > .91 Temp = CStr(Int(X) + 1) End Select Num2Frac = Temp End Function

Function Num2FracA (ByVal X As Double, _                         ByVal Denominator As Long) As String Dim Temp As String, Fixed As Double, Numerator As Long X = Abs(X) Fixed = Int(X) Numerator = Int((X - Fixed) * Denominator + .5) ' Rounding If Numerator = Denominator Then Fixed = Fixed + 1 Numerator = 0 End If       If Fixed > 0 Then Temp = CStr(Fixed) If Numerator > 0 Then Temp = Trim$(Temp & " " & Numerator & "/" & Denominator) End If       Num2FracA = Temp End Function

Function Num2FracB (ByVal X As Double, _                         ByVal Denominator As Long) As String Dim Temp As String, Fixed As Double, Numerator As Long Dim Factor As Long X = Abs(X) Fixed = Int(X) Numerator = Int((X - Fixed) * Denominator + .5) ' Rounding If Numerator = Denominator Then Fixed = Fixed + 1 Numerator = 0 End If       If Fixed > 0 Then Temp = CStr(Fixed) End If       If Numerator > 0 Then Factor = GCF(Numerator, Denominator) ' Factor for normalization. Temp = Trim$(Temp & " " & Numerator / Factor & "/" & _                      Denominator / Factor) End If       Num2FracB = Temp End Function

Function GCF (ByVal X As Long, ByVal Y As Long) As Long '     ' Returns the Greatest Common Factor. ' The largest number that will evenly divide into both X and Y.     ' Dim Temp As Long X = Abs(X)       ' Make both numbers positive. Y = Abs(Y) Temp = X Mod Y       Do While Temp > 0 X = Y         Y = Temp Temp = X Mod Y       Loop GCF = Y     End Function  Run the project and then press CTRL+BREAK to pause. In the Debug/Immediate window, type the following:

?Num2Frac(3.54), Num2FracA(3.54,8), Num2FracB(3.54,8)

Results:

3 1/2

3 4/8

3 1/2



