How to Make a Secret Code Worksheet
Use secret code worksheets as a fun activity for kids as well as a way to help them develop analytical and logical thinking skills. Students will enjoy decoding the secret messages, and probably will want to invent codes of their own for writing letters to friends. Let the fun begin with a simple secret code worksheet. You might realize that you enjoy writing in code as much as the kids do!
Instructions
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Make a Secret Code Worksheet
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Come up with several different codes. Make a shift code by writing out all the letters of the alphabet in one neat row, and then write the same letters in a second row below with the letter "a" somewhere other than in the first spot. For example, you might place the letter "a" in the eighth spot (under the first row's letter "h"), and then continue writing the letters in alphabetical order. This is a shift code in which the alphabet has been shifted over seven units. The letter "t" should then appear in the first spot, under the first row's letter "a." Encrypt a message by exchanging each letter from row one with the new letter that appears below it in row two. "A" will now be "t," and "h" will now be "a." The message, "Today is Tuesday" will appear as "Ahwts bl mnxlwts."
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2
Make a few different codes before you make your worksheet. Try a numbers code in which each number stands for a letter. You can simply assign the letter "a" number one, "b" number two and so on, or you assign the letter "q" number one, "r" number two and "s" number three and so on. Assigning numbers to letters in increasing order, no matter which letter you begin with, will make the code easier for kids to break. Random substitution codes are much more difficult to break than either the shift code described in step one or the number code described above. In a random substitution code, each letter is replaced with a number or letter without alphabetical or numerical order. For example, "a" becomes "c," "b" becomes "s," "c" becomes "w" and so on. You can also design substitution codes in which you replace each letter with an image or simple symbol.
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3
Write several coded messages in each code you have made on your worksheet. Use a few different shift codes, a number code and, for added challenge, a random substitution code. Depending on the level of your students, you might want to give them a hint by including the number of units the alphabet was "shifted" by in each shift code. When students are given no clues, they can begin breaking the code by looking at the messages' two or one-letter words, as well as repeated letters in individual words. These words will help them solve the code. For example, a single letter word has to be the letters "a" or "I." Photocopy the completed worksheets on colorful paper for a fun look.
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Let students write their own codes once they have decoded the messages on your worksheet. They can practice by writing shift codes, but they might particularly enjoy coming up with mysterious-looking symbols for a random substitution code. Have students exchange their own coded messages for more decoding practice.
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