ACARA Digital Technologies Years 5–6 Word Scramble: Representing Data with Numbers (Modules 59–71)
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Word scramble
Unscramble the letters and write each key term on the line.
1
EUH-TRNNLG IDNGOEDC
Turn counts back into pixels: write that many of one colour, then that many of the other, taking turns, until the row is full. Start with white. A first count of 0 means the row starts black.
2
GTN-UELRNH IONEDGCN
Counts each run of one colour instead of listing every pixel. It saves space on long runs, like an all-white row, but saves little when colours change every pixel, like a checkerboard.
3
1 TBI = 2 ULSROOC
One bit per pixel can only be 0 or 1, so each pixel can only be one of two colours, like black and white. A photo needs many more colours, so it needs more bits.
4
00 10 01 11
Two bits per pixel make four codes, so each pixel can be one of four shades: 00 is black, 01 is dark grey, 10 is light grey and 11 is white.
5
B^IT2S
Each extra bit doubles the colours a pixel can show: 1 bit gives 2, 2 bits give 4 and 3 bits give 8. So the number of colours is 2 times itself, once for each bit.
6
RUOOLC YKE
A list that matches each whole number to a colour, like 1 = red, 2 = blue and 3 = yellow, so a grid of numbers can show a picture.
7
EEDCDO
To ______ a grid of numbers, look up each number in the colour key, then colour that square the matching colour. Doing this for every square rebuilds the picture.
8
LIFL LRCOUO
A spreadsheet tool that changes the background colour of the selected cell or cells. Click one cell or drag over a block, then pick a colour. Choose No fill to remove the colour.
9
UONLMC HTWID = ORW GHTEIH
Set the column width and row height to the same size so each cell is a square. A block of square cells then looks like a pixel grid.
Answer Key
ACARA Digital Technologies Years 5–6 · Modules 59–71
1EUH-TRNNLG IDNGOEDC → run-length decoding — Turn counts back into pixels: write that many of one colour, then that many of the other, taking turns, until the row is full. Start with white. A first count of 0 means the row starts black.
2GTN-UELRNH IONEDGCN → run-length encoding — Counts each run of one colour instead of listing every pixel. It saves space on long runs, like an all-white row, but saves little when colours change every pixel, like a checkerboard.
31 TBI = 2 ULSROOC → 1 bit = 2 colours — One bit per pixel can only be 0 or 1, so each pixel can only be one of two colours, like black and white. A photo needs many more colours, so it needs more bits.
400 10 01 11 → 00 01 10 11 — Two bits per pixel make four codes, so each pixel can be one of four shades: 00 is black, 01 is dark grey, 10 is light grey and 11 is white.
5B^IT2S → 2^bits — Each extra bit doubles the colours a pixel can show: 1 bit gives 2, 2 bits give 4 and 3 bits give 8. So the number of colours is 2 times itself, once for each bit.
6RUOOLC YKE → colour key — A list that matches each whole number to a colour, like 1 = red, 2 = blue and 3 = yellow, so a grid of numbers can show a picture.
7EEDCDO → decode — To decode a grid of numbers, look up each number in the colour key, then colour that square the matching colour. Doing this for every square rebuilds the picture.
8LIFL LRCOUO → fill colour — A spreadsheet tool that changes the background colour of the selected cell or cells. Click one cell or drag over a block, then pick a colour. Choose No fill to remove the colour.
9UONLMC HTWID = ORW GHTEIH → column width = row height — Set the column width and row height to the same size so each cell is a square. A block of square cells then looks like a pixel grid.