Challenge type: Pixel Puzzles · Difficulty: ★★★☆☆ Medium · Grid: 9 × 9 · Colours: 2
Pixel the cat loves this kind of puzzle. Each number stands for a colour. What picture is hiding in the grid?
The colour key
- 1 = yellow
- 2 = orange
- 0 (shown as ·) = leave it white
The number grid
Here’s the same grid as a table. You can copy it onto squared paper, one number per square.
| Row | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
|---|---|---|---|---|---|---|---|---|---|
| 1 | · | · | · | · | 1 | · | · | · | · |
| 2 | · | 1 | · | · | 1 | · | · | 1 | · |
| 3 | · | · | 1 | 1 | 1 | 1 | 1 | · | · |
| 4 | · | · | 1 | 2 | 2 | 2 | 1 | · | · |
| 5 | 1 | 1 | 1 | 2 | 2 | 2 | 1 | 1 | 1 |
| 6 | · | · | 1 | 2 | 2 | 2 | 1 | · | · |
| 7 | · | · | 1 | 1 | 1 | 1 | 1 | · | · |
| 8 | · | 1 | · | · | 1 | · | · | 1 | · |
| 9 | · | · | · | · | 1 | · | · | · | · |
Need a hint?
The picture is the sun! Start with the colour that appears most, then fill in the details.
Grown-ups: Print the grid picture or copy it onto squared paper. This is exactly how images are stored: a grid of numbers, where each number means a colour. It’s a lovely calm activity for younger children too.
For teachers and grown-ups
Skills practised: Data representation, following a key, and attention to detail.
The big idea: A digital picture is a grid of numbers. Each number stands for a colour.
Questions to ask:
- How many pixels are in this picture?
- Which colour appears most often?
- How could you describe the picture in fewer numbers? (Hint: count runs of the same colour.)
Take it further: Children design their own pixel picture on squared paper and write it out as numbers for a partner.