# Computer Science Unplugged

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This activity shows learners how computers use numbers to represent pictures. A grid is used to represent the pixels (short for picture elements) of a computer screen.

1 cent - \$1 per student Ages 6 - adult 30 to 45 minutes
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This activity helps students learn how computers "compress" text by identifying repeating patterns of letters, words, and phrases.

1 cent - \$1 per student Ages 8 - adult 30 to 45 minutes
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This magic trick is based on how computers detect and correct data errors.

1 cent - \$1 per group Ages 8 - adult 30 to 45 minutes
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In this activity, learners listen to songs and decode hidden messages based on the same principle as a modem. As a final challenge, learners decode the binary messages in a music video.

free Ages 6 - 18 30 to 45 minutes
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In this computer science activity about finite-state automaton (on page 45 of the PDF), learners use a map and choose various pathways to find Treasure Island.

1 cent - \$1 per student Ages 8 - 14 45 to 60 minutes
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In this activity, learners will explore how product barcodes are scanned accurately and be able to "guess" the last number in a 13 digit barcode correctly every time.

\$1 - \$5 per group Ages 6 - 14 10 to 30 minutes
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This activity about cryptographic techniques illustrates how to accomplish a simple, but nevertheless seemingly impossible task—making a fair, random choice by flipping a coin between two people who d

\$1 - \$5 per group Ages 8 - 18 30 to 45 minutes
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This activity about cryptographic techniques illustrates a situation where information is shared, and yet none of it is revealed.

1 cent - \$1 per group Ages 11 - adult 5 to 10 minutes
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In this activity, learners play a game similar to Hangman by guessing a secret phrase to understand how computer scientists measure the amount of "information" in a document.

1 cent - \$1 per group Ages 6 - 14 5 to 10 minutes
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In this activity, one person acts as a human robot while another acts as their developer by programming their actions.

\$1 - \$5 per group Ages 6 - 14 10 to 30 minutes