Nathan B. answered • 09/08/16

Elementary and Algebraic skilled

Since we cannot have a 0 in our digits, let's look at the other numbers starting with 1:

1 + 8 = 9

2 + 8 = 10

Since using two gives us a 0 (and two digits of its own), we're left with only 1:

_1

And since 1 + 8 = 9, that means that 9 is in the tens' place:

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