# Digit Place (A Secret Number Quest)

by Jamee Petersen, Author, Math Solutions
October 17th, 2017

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Develop students’ number sense, place value, and deductive reasoning with A Secret Number Quest, a short game that all students will love. The game begins with one player selecting a secret number, which their partner then tries to guess. After each guess, the player with the secret number reveals whether the number guessed shares a digit with the secret number. If it does, the player also reveals whether the place value is correct. Play continues until the number is guessed correctly.

### Materials

• Digit Place (A Secret Number Quest) Recording Sheet (Figure 1), 1 per group of students
• pencil, 1 per group of students

## Directions

### Part 1: Mock-game

1. Select a student to be your partner and display figure 1 on the board. Explain that for the purpose of learning the game, you will start by sharing the secret number with everyone. Choose the number 42.
2. Next, show students how you record a guess. Say, “Let’s pretend my partner guessed fourteen. I record the number fourteen in the Guess column.” Write 14 in the Guess column of the enlarged recording sheet.
3. Now add information about how many digits and places are correct based on the number 14 guess. Say, “I now write a one in the Digit column because one of the digits, the four, is correct. I write a zero in the Place column because the four in fourteen is not in the correct place. The four is in the one’s place, not the tens place.” Your chart should look like this:
4. Continue demonstrating making guesses and writing corresponding information on the chart until the secret number is figured out. Make many different guesses and carefully narrate your reasoning as you record.
5. Ask key questions like: “After your last guess, what do you know for sure?”

### Part 2: Groups

1. Place students in small groups of four.
2. Explain to students that one pair will decide on a secret number. The other pair will make guesses and discuss after each guess “what they know for sure.” Working together helps students avoid errors in conveying information about digit and place.
3. Give each group a copy of the Digit Place Recording Sheet (Figure 1). As students play, circulate, observing and assisting as needed.

Figure 1. Digit Place Recording Sheet

Adapted from Math Games for Number and Operations and Algebraic Thinking, Grades K–5 by Jamee Petersen. Math Solutions