Exacto
15 boards have two holes each and color dots on the front. For a round, two boards are laid out, one front side up, the other backside up, showing a distance. The active player looks at the boards - he must not pick them up - and names the two colors that he believes will show exactly and to the millimetre in the two holes. In case of a wrong tip, the next player has a guess. In case of a correct tip, you take the board showing the backside, the other goes back under the stack and two new cards are laid out for the next player. When only one board is left, you win with most boards.
Assessment game for 2-6 players, ages 5+