The Scratch sandbox

The sandbox is a full Scratch editor at scratch.shuleone.co.ke, used for the block-based part of the coding pathway.

You do not normally go there directly. A coding lesson or project opens it for you, with the right starter project already loaded, and your work comes back to the portal when you save.

The editor

If you have used Scratch before, this is the same editor:

• Blocks palette on the left — the blocks you can use, grouped by colour.
• Script area in the middle — where you drag blocks to build.
• Stage at the top right — where your project runs.
• Sprites below the stage — the characters and objects in your project.

Drag blocks from the palette and snap them together. Press the green flag to run, the red stop sign to stop.

Saving and submitting

Save sends your project back to the portal. Do this often — as often as you would save any other work.

For a project stage, saving is not the same as submitting. Save keeps your work; submit hands it to your teacher. Go back to the portal to submit when you are finished.

Caution

Do not close the sandbox tab without saving. The editor holds your work in the browser until you save it back, and a closed tab loses whatever has changed since the last save.

Working on a project

Start small and run often. Build one thing, run it, check it does what you expected, then add the next thing. A project built entirely before its first run is very hard to debug.

Name your sprites. “Sprite1”, “Sprite2” and “Sprite3” become confusing within about ten minutes.

Use comments. Right-click in the script area to add one. Your future self, coming back after a week, will not remember why that wait block is there.

Test the awkward cases. What happens if the player presses two keys at once, or clicks before the game starts? This is the kind of thinking the pathway is teaching.

When something does not work

Problem	Usual cause
Nothing happens on the green flag	No when green flag clicked block at the top of the script.
A sprite disappears	It has moved off the stage, or its size or visibility changed.
The project runs once and stops	Something needs a forever or repeat around it.
Blocks will not snap together	They are different shapes — the shape tells you where a block can go.
Your work is not in the portal	It was not saved back before the tab was closed.

Using it on a phone

Scratch needs dragging, and it is genuinely awkward on a small screen. A tablet works; a phone is frustrating. If a phone is what you have, do the reading and quiz parts of the lesson on it and save the building for a larger screen.