N[variable,2] displays 6 digits

Question

The following code doesn't behave as I expect. Rather than getting 2 digits upon varying r, I get the default value of 6 digits. What's up?

Manipulate[ 
 eq = Row[{"(-\[Infinity], ", N[1/r, 2] ")"}];
 Show[Graphics[{Black, Text[eq]}]],
 {{r, 1}, 0.5, 5, 0.1, Appearance -> "Labeled"},
 Initialization :> (y[t_, r_] := 1/(1 - r t);)]

This code is a snippet from a larger Manipulate.