Five pages on coding and decoding, a standard chapter in logical reasoning workbooks and olympiad tests. Page 1 writes and cracks the next-letter code, where each letter becomes the one after it. Page 2 has eight multiple-choice questions in the familiar "If CAT is written DBU, how is PIG written?" form, using next-letter, back-one, two-ahead and backward codes. Page 3 uses the number code A = 1 to Z = 26, adds up the letters of words, and works out a digit code from examples such as ROSE = 6821. Page 4 practices backward and two-ahead codes. Page 5 solves word-swap codes, where words stand for other words, and finds the rule of four codes. The first item on each page is done as an example.
Write CAT and DBU on the board and ask the class how each letter changed. Then try one word in each of the four codes before page 2, so students know the rules to test: one letter ahead, one letter back, two letters ahead, and backward. On the word-swap questions, model reading slowly: grass is green, and in this code green is called yellow.
Pick a code from the pack and write a short note to your child in it, then ask for a reply in the same code. A favorite game: one person codes a word, the other has to find the rule and the word.
This pack supports the following Common Core State Standards for Mathematics:
© Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.
Coding and decoding, the logical reasoning topic of letter and number codes. Students crack letter-shift and backward codes, answer olympiad-style questions, use the number code A = 1 to Z = 26 and find a code's rule.
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