1. Today you will need… A pencil Your math journal Snap cubes, color tiles, or counters

2. This is a secure area. Only math detectives will be able to pass.

3. “I didn’t know that all of you were detectives.” “Well, it turns out the Number Nabber has struck again!”

4. “That’s right! The Number Nabber and this time it’s pretty bad. It seems that most of the numbers that he took are less than 10. But, we can’t be sure.”

5. “It seems that he took the numbers from a factory that makes ‘Number Triangles’.”

6. “These Number Triangles are used by scientists to build calculators and other number machines.”

7. “Although we might not be able to catch him, we have to discover which numbers have been taken so that we can replace them.”

8. “The good news is he left some pretty big clues.”

9. “I’ll show you the number triangles he left behind.” “Work with a partner to discover the missing numbers.”

10. “I’ll show you the number triangles he left behind.” “Work with a partner to discover the missing numbers.” “Remember, the three numbers in a triangle are connected….somehow.” “You may use any tool you need to to solve the case.”

11. “And remember, the chief will need to see some proof of how you found your solutions.” “I suggest pictures, numbers, and words.” “Good luck!”

12. 6 15 A 7 D 13 9 G 9 C 14 5 F 9 16 I 8 12 B 9 17 E 146 H

13. “The chief is going to need your report soon.” “As you get ready for the report, look for any possible patterns in the triangles.” “The patterns might be a clue to figuring out what the Nabber will be going after next.”

14. “So who do you think the ‘Number Nabber’ is? Why do you think that he steals numbers?” Write a description of the Number Nabber telling things about him so that citizens can be on the lookout for him. It would be a good idea to include an illustration of the Nabber.

15. Hopefully your descriptions and illustrations will lead to the arrest of this criminal mastermind.