My alien friend said "do you think our system is strange? You need to have a look at our neighbour country, this is how they do it...", and then he showed me their neighbour's system (which was also a decimal system). For addition:

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Then, multiplication:

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At first I was puzzled, but that ended up being an easy one: I remembered the ancient Greeks at my home planet and now I can explain it. Can you?


1 Answer 1


The numbers are read

alternating between left-to-right and right-to-left

So the sum is actually:

42 + 71 + 104 + 61 + 9 = 287

And the product is actually:

8 × 19 × 24 × 104 = 379,392


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