Online worksheet · 3 of 4
Seeing needs light entering the eye - Online practice 3
Read the information, then answer the questions. An adult may read the instructions aloud. Show your working where asked.
Read before answering
Seeing model: light from torch reaches a non-luminous card; some light reflects from it into an eye. Non-luminous means the object is not making its own light in this situation. In air, the simple model uses straight paths between interactions. This is a paper task: never look at the Sun or aim lights into eyes.
Open your writing and drawing pad
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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.
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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.