Mystery Number - 4GT

Grade 4GT 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.
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 gathers the students up front with their journals and reminds them of how the routine works. After the first clue, the teacher walks around checking the students are working as she gives think time. After the second clue is revealed, the teacher re-reads it and tells the class to think about place value as they are checking to see if their number satisfies that clue. After the third clue is revealed, a student asks for clarification of a word and the teacher facilitates a discussion on what the word means and how to tell if a number satisfies that clue. Notice as the students continue to work, the teacher checks in quietly with some students that may need a little extra support. After all the clues have been revealed, the teacher groups the students to share and defend their final guesses with one another. Notice how during the small discussion a student realizes an error she made and changes her guess. After the pair talk time, the teacher asks for all guesses and records them on the board. A student asks for clarification on a clue and the class works through what it means. Then the teacher allows for students to respectfully disagree with guesses shared and explain why. The students turn back to their groups and discuss if any numbers are missing. After sharing out the missing numbers, a student points out a pattern that they noticed.

GOOGLE SLIDES: Mystery Number Links to an external site.

These slides include directions and 28 different sets of clues for a mystery number. The clues and numbers progress along with the standards as taught throughout the year.