Wiring size

Question

First, let me say I have been working in the electric field for over 40 years. Here's my dilemma. I bought an electric stovetop to replace a gas one. The directions are telling me to use #8 wire with a 40 amp breaker. The problem is the wire coming out of the stovetop is #10. Either directions are wrong or I am missing something. Did you ever see this?