Grade 5, Chapter 3 Investigation Organizer:

**1. Plan It**

**A. Start your code.** List the letters of the alphabet. Leave five lines blank after each letter.

**B. Write a number. ** Below each letter, write a number.

- A will be 1.
- B will be 2.
- C will be 3, and so on.

** Our list completed**

**2. Put It Together**

**Keep coding!**

Take your time while completing each of the following steps.

** 2.** Remove the multiplication sign to get the code number. For C, the code number will be 13.

** 3. **To make your code different from the codes of other groups, multiply each code number by a number between 11 and 25. For example, if you picked 11, C would become 13 x 11, or 143.

** Coding completed**

**3. Wrap It Up**

**A. Use your code.** Use your group's number code to write a sentence. You can use a sentence in a book, or make one up. Separate each number that represents a letter with a slash.

**B. Use your decoding power.** Exchange your coded sentence with another group. See which group can decode the other group's sentence first.

** Decoding completed**

**4. Discuss Your Results**

- Did you use your math skills to create and decipher codes?
- Is your factoring list clear and correct?
- Is your coded sentence accurate?
- Did your group organize and divide the work fairly?
- What other mathematical ideas could be used to create a code?

** Review completed**

Return to Investigation Page.

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