I'm not sure I'd give such an absolute statement of certainty as the GP, but there is little reason to believe that consciousness and intelligence need to go hand-in-hand.

On top of that, we don't really have good, strong definitions of "consciousness" or "general intelligence". We don't know what causes either to emerge from a complex system. We don't know if one is required to have the other (and in which direction), or if you can have an unintelligent consciousness or an unconscious intelligence.

You do not need to implement consciousness into a calculator. There exist forms of intelligence that are just sophisticated calculation - no need for consciousness.