lesson
A decision may need checking again
1 · Learn
An if statement checks a condition when execution reaches it. If the input later changes, the program will not notice unless it checks again. Repetition can make repeated checking possible.
In a continuing loop, read the input, choose an output, then check again at an appropriate pace. Provide a stop control and avoid rapid flashing or excessive sound.
2 · Worked example
A model button is not pressed at the first check. A one-time script ends. A repeated-check script can respond when the button is pressed later.
3 · Your turn
Why might checking a button only once miss a later press?
Check your answer
The program has already passed the decision. It must reach another check to respond to the later input.
4 · Apply your learning
Compare one-time and repeated checks in an approved tool. Use a gentle on-screen colour or text change, not rapid flashes.
Adult guidance and safety
Use adult-approved offline or school-managed tools, invented data and original media. Keep projects private unless sharing is explicitly approved. Paper traces support, but do not replace, practical programming and saved digital work. No real passwords or personal records belong in these exercises.
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Write, draw or show your working. Use a mouse, pen or finger. This pad is not a submitted answer.
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Open a picture saved on this device to draw on it again. Opening replaces the drawing, but Undo can restore it. PNG only, up to 4 MB and 4096 × 4096 pixels. The picture stays in this browser; it is not uploaded. Paper lines in a saved picture become part of that picture.
Clear the drawing? Your typed notes will stay. You can undo this action.
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Open a UTF-8 TXT file from this device, up to 40 KB and 10,000 characters. It stays in this browser. Opening can be undone until you type again. Downloads keep a new copy; they do not change the file you opened.
Replace the notes on this page with the opened file? Download the current notes first if you want to keep them.
Typed notes are not submitted answers.
Check a calculation · Year 5 onward
Use this only when your teacher or adult allows a calculator for the task. Show your thinking first. It does not replace mental or written arithmetic and does not mark your lesson answer.
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