Round each contextual number by choosing one of its two bounding multiples.
Supported keeps the midpoint visible. Building mixes nearest 100 and 1,000. Midpoint focus contrasts just below, exactly at and just above halfway. Mixed challenge mixes nearest 10, 100 and 1,000 with minimal support. Large numbers mixes nearest 10,000, 100,000 and 1,000,000 across the full range to 10,000,000.
In Team mode, teams take one card each in rotation and score one point for a correct choice. There is no timer. New game keeps your settings; Reset restores the original Practice game.