During our travels around the galaxy we found many alien cultures with different number systems. However, this specific civilization was quite interesting: they had a decimal numeral system, just like ours! To facilitate communications we learnt their decimal numerals and they learnt ours (0, 1, 2, etc...), along with the operators (+, -, ect...).
My alien friend showed me this...
(a) 2 + 2 = 4
...which was correct, as well as this:
(b) 1 + 5 = 6
And I thought it was all settled. But then they showed me this:
(c) 19 + 24 = 331
Which cannot be correct! Then, they came with:
(d) 28 * 17 = 2285
At that point I stopped them, saying "no, this is not right!". We sat down and they showed me the calculations step by step, and then I realised my mistaken assumption!
Now I can explain c
and d
. Can you?