Q2-calculation

Dim a As Double = TextBox1.Text
        Dim b As Double = TextBox2.Text
        Dim c As Double = TextBox3.Text
        Dim big As Double
        Dim sma As Double

        sum.Text = " " & a + b + c
        avg.Text = " " & (a + b + c) / 3

        If (a > b And a > c) Then
            big = a
        ElseIf (a = b Or a = c) Then
            big = a
        ElseIf (b > a And b > c) Then
            big = b
        ElseIf (b = a Or b = c) Then
            big = b
        ElseIf (c > a And c > b) Then
            big = c
        ElseIf (c = b Or c = a) Then
            big = c
        End If

        If (a < b And a < c) Then
            sma = a
        ElseIf (a = b Or a = c) Then
            sma = a
        ElseIf (b < a And b < c) Then
            sma = b
        ElseIf (b = c Or b = a) Then
            sma = b
        ElseIf (c < a And c < b) Then
            sma = c
        ElseIf (c = b Or c = a) Then
            sma = c
        End If

        small.Text = " " & sma
        bigL.Text = " " & big
        product.Text = " " & big * sma