Mystery Number - 2

Grade 2 mathematics Routine

Mystery Number

Standards for Mathematical Practice: #1, #2, #3, and #7

In this routine, students compare similarities and differences in numbers through several clues.  Students will experience that there may be more than one correct answer for a clue. It comes from Daily Routines to Jumpstart Math Class (Corwin, 2019).

DIRECTIONS:

1. Students will need their journals and a pencil or a whiteboard and markers, and possibly a 100 chart.
2. Present the first clue ( students should only see one clue at a time).
3. Ask the students to identify and write a number that satisfies the clue.
4. Solicit and record student solutions for the first clue. 
5. Discuss how each of the solutions relates to the clue.  
6. Present the next clue.  If a student's original number satisfies the clue, then they should put a check next to it.  If the student's original number does not satisfy the clue, they should change it so it does.  They should not erase their first number, but add the new number under it in a list format.
7. Solicit and record new solutions.  
8. Repeat the process for the rest of the clues.
9. The following are questions you may want to ask.

• • How does (number) satisfy each of the clues?
  • How is this number similar to the other numbers that are satisfying the clues?
  • What next clue might eliminate ( give a specific number)?

VIDEO:

Notice how the teacher reminds the students about what will happen during the routine and has the materials already prepped for what each student will need. (a clipboard, hundreds chart, and sticky note) After the first clue, the teacher highlights how a student is using a hundreds chart to help them narrow their guesses down. When the students each think of a number, the teacher uses partner talk for them to discuss their ideas with one another. As she asks for people to share out, notice how the teacher tells the class how many students will share their number. As the next clue is revealed, the teacher facilitates a discussion to ensure the students understand what the clue means. After three clues, the teacher has the students share their numbers with their partners to see if they agree that the number satisfies all the clues given so far. As the last clue is revealed, the teacher explains what the clue means and gives the students time to work through finding the correct mystery number. After they discuss the number, the teacher highlights all the great behaviors she noticed as the students worked through the mystery. 

GOOGLE SLIDES: Mystery Number Links to an external site.

These slides include directions and 25 different sets of clues for a mystery number. The clues and numbers get more challenging as the deck progresses.