Solution for a hallucinating calculator: get a second unreliable calculator to verify the work of the first one. This message brought to you by a trillion dollars in investment desperately trying to replace the labor force with pseudo-intelligent calculators.

Also, the calculator may refuse to process certain operation deemed to be offensive or against the interest of the corporate-state.

Not to forget, the calculator consumes so much processing power that most people are unable to run it at home, so you need a subscription service to access general-purpose calculation.