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I've thought of a rule.
Numbers that obey my rule will light up the light.
Try entering some numbers.
Can you determine the rule?
This activity is featured in the second half of Alan Parr's article Rocking Chairs, Railway Games and Rayboxes.
See the Light
Age 7 to 14
Challenge Level 
I've thought of a rule.
Numbers that obey my rule will light up the light.
Try entering some numbers.
Can you determine the rule?
This activity is featured in the second half of Alan Parr's article Rocking Chairs, Railway Games and Rayboxes.
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