The purpose of this activity is for students to learn a new center called Mystery Number. One student picks 2 cards and makes a two-digit number without showing their partner. They give clues about the mystery number based on the sentence starters and their partner guesses the mystery number. Students continue going back and forth giving clues and guessing the number until the mystery number is identified. Then students switch roles. Students earn 1 point for each clue they get to help them identify the mystery number. The player with the lowest score after 5 rounds wins.