Originally calculators used seven small lights (or LEDs) to form the digits 0 to 9.
1. Which light is used most?
2. Which light is used least?
3. Which letters of the alphabet could be represented using this system?
4. How many different combinations of 'on' and 'off' can these seven lights make?
Topics: Starter  Calculator  Investigations  Mixed
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Here is an interactive version of a digital display. Click the lights to turn them on or off.
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