To a computer, a photo, a song and a story are all the same thing: numbers. At Pixel Plaza, Year 4 coders find out how pictures are built from pixels and how everything is stored as bits and bytes.
What your child will learn
- Know that digital pictures are made of pixels
- Know that computers store all data as 1s and 0s
- Use the words bit, byte, kilobyte, megabyte and gigabyte
- Recognise common file types and why files are kept in folders
Pictures from squares
Zoom far enough into any digital picture and you will see tiny squares called pixels. Each pixel’s colour is stored as numbers. More pixels give a sharper picture, but a bigger file.
Bits and bytes
A bit is a single 1 or 0. Eight bits make a byte, enough to store one letter. About a thousand bytes make a kilobyte, about a thousand kilobytes make a megabyte, and about a thousand megabytes make a gigabyte.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. Which of these is most likely a sound file?
- photo.png
- scores.csv
- letter.txt
- song.mp3
Show answer
Answer: song.mp3. Files ending in .mp3 are sound.
2. Where is a file kept after the computer is switched off?
- On the storage drive
- In the speaker
- On the screen
- In the mouse
Show answer
Answer: On the storage drive. Saved files stay on the storage drive until you delete them.
3. Which picture will look sharper?
- One with more pixels
- One with fewer pixels
Show answer
Answer: One with more pixels. More pixels can show finer detail.
Tips for grown-ups
- Colour squares on grid paper to make pixel art, then write each row as 1s and 0s.
- Zoom right into a photo on a phone or tablet until the pixels appear.
- Look at the sizes of a text file, a photo and a video on your computer and compare them.