Data Representation

Lesson 4

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StarterLink up the foreign words to the flag of origin

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1. Shukran2. chnorakaloutioun3. hvala4. Merci5. Danke6. Kiitos7. Hvala8. Tak9. děkuji10. dank u11. Tänan12. Gràcies

Objective of the lessonTo be able to convert binary numbers to letters and

words.

• All of you will:

• Be able to convert binary numbers into letters.

• Most of you will:

• Use binary to create words

• Some of you will:

• Convert RGB to Hexadecimal

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• Create your own way of sending a secret message

• Write a coded message

• Give instructions to decode it

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Homework

Last lesson…

• You worked in teams to talk about different areas of data representation.

• Over the next two lessons we will be focussing on some of the important areas of data representation.

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Today

• You will decode a binary message and provide an answer

• Use the ASCII code sheet to decode the binary message

Step 1. Convert to ASCII values

Step 2. Convert ASCII values to letters

Step 3. Convert response back into binary

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Hexadecimal• Hexadecimal codes are used to simplify binary

codes.

• Computers do not use hexadecimal – Humans use it to shorten Binary

• Hexadecimal is translated into binary for computer use. – colour references

– assembly language programs

– error messages

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All Colours are created equal

• To create colours we mix together the primary colours

• What are the primary Colours?

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Green

Blue

Red

As we know a computer needs a numerical value to process

RGB provides computer scientists with a range of numbers: 0 to 256

What is the total numbers of colours in the spectrum?

What is the square root of 256?

Hex Colours

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0 1 2 3 4 5 6 7 8 9 A B C D E F

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Hexadecimal is base 16

Color Decimal Code(R,G,B) Hex Code #RRGGBB

Black (0,0,0) #

White (255,255,255) #

Red (255,0,0) #

Lime (0,255,0) #

Blue (0,0,255) #

Yellow (255,255,0) #

Cyan / Aqua (0,255,255) #

Magenta / Fuchsia (255,0,255) #

Silver (192,192,192) #

Gray (128,128,128) #

Maroon (128,0,0) #

Olive (128,128,0) #

Green (0,128,0) #

Purple (128,0,128) #

Teal (0,128,128) #

Navy (0,0,128) # 10

Plenary

• What is the ASCII value for the letter T

• What is the ASCII value for the 01110111

• What colour is #FF0000?

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• Create your own way of sending a secret message

• Write a coded message

• Give instructions to decode it

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Homework

StarterLink up the foreign words to the flag of origin

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1. Shukran2. chnorakaloutioun3. hvala4. Merci5. Danke6. Kiitos7. Hvala8. Tak9. děkuji10. dank u11. Tänan12. Gràcies

13. German14. French15. Estonian16. Czech17. Arabic18. Bosnian19. Catalan20. Armenian21. Bulgarian22. Croatian23. Danish24. Finnish25. Dutch