Whenever I try voice calculation, the game doesn't recognise when I say the number 6, so either I cannot continue or I waste time repeating myself until it recognises it, making an invalid result. I've tried putting on various accents and tones of voices, and I've also varied the distance from the microphone but these don't make a difference.
Yes, the voice recognition is most problematic for that minigame. I have the same problem you do. --- M. Bison wears a red cap, throws fireballs, does head stomps, and cape flicks. Clearly M stands for Mario.