Why this code doesnt work?

why this code doesn't work?? if i put k += 1 it gives the correct anwer k = 6 *Whats going on? Sub Main() Dim m As Double(,) = {{6, 2, 6}, {1, 3, 7}} Dim k As Double Dim A0 As Double Do Until A0 = 1.0 k += 0.1 A0 = m(0, 0) / k Loop Console.WriteLine("k is " & k)