How on earth does this work?

I honestly have no idea…it got me everytime..dark magic, I say!

It didn’t work for me.

The same gift is listed on those numbers it could be: 9, 18, 27, 36… (multiples of 9).
Mathematically, its gonna be one of those.

@filmfann got it! They change the answer each time you do it so it seems different, but if you look at any previous number you tried, you’ll see it’s the same “gift” as the current number.

@klutzaroo if it didn’t work for you, then your arithmetic was wrong on the subtraction.

If your two-digit number was 11, for example, and you subtract 1 and 1 (per the instructions), then you’re left with 9. Any number up to 19 gives the same answer: 19 – 1 – 9 = 9. Numbers from 20 to 29 yield 18, and so on, as @filmfann noted. So all of the “regifts” at the multiples of 9 are exactly the same, and those are the only ones that Robin has to “predict”.

@WasCy – I just realized that myself.

Mine was 9. I noticed that if you added up the digits of hers, they also equal 9. I thought of another – and inevitably, that also added up to 9 (the two digits).

I thought that was the trick, but “99” is an answer as well, and that equals 18 when added up (although add that up, and it equals 9 again), so @WasCy has it with the multiples of 9.

It also regenerates with a new gift each time at that number, so it’s not obvious (i.e., since the chart changes, you’ll get a different gift in the 9 multiple box).

I’ll note that it’s super-transparent if you realize that subtracting the two digits from a two-digit number means that the highest choice should be 81 – 99–9-9.

I don’t know. I don’t think my nervous system is wired to tolerate the pitch, tone and tempo of Regifting Robin’s voice. I couldn’t finish listening to her even when I turned the volume down. Maybe it’s just me.

So subtracting the one’s column digit reduces it to a multiple of ten. Subtracting the value of the ten’s column (x) makes it the same as 10x – x = 9x So whatever your number is, it’s a multiple of nine.

Thanks guys! I honestly was baffled, so I appreciate you explaining the math behind it.