Sub CalculateSum()
Dim x As Double, s As Double, t As Double, i As Integer, n As Integer
x = 0.5
s = 0
t = 1
i = 0
Do
s = s + t
If t <= 0.0001 Then Exit Do
t = t * x
i = i + 1
Loop
n = i + 1
' Красивый вывод
Range("A1").Value = "Сумма ряда (x=0,5) с точностью ≤0,0001:"
Range("B1").Value = Round(s, 4)
Range("A2").Value = "Количество слагаемых:"
Range("B2").Value = n
Range("A1:B2").Font.Bold = True
Columns("A:B").AutoFit
End Sub