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Special Numbers
My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?
Your Number Is...
Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?
First Forward Into Logo 6: Variables and Procedures
Learn to write procedures and build them into Logo programs. Learn to use variables.
Age 11 to 14
Challenge Level
One way to begin thinking about this is to collect together some outputs and their corresponding inputs:
| Finishing Number | Starting Number |
Can you write each step of the machine's instructions as a function machine?
What happens if you work backwards?
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NRICH is part of the family of activities in the Millennium Mathematics Project.
NRICH is part of the family of activities in the Millennium Mathematics Project.