-1 2/3 + 4 1/6

To add these two mixed numbers, we first need to convert the fractions into the same denominator.

1. For -1 2/3, we have -1 + 2/3
2. For 4 1/6, we have 4 + 1/6

Now we add:

-1 + 4 = 3

2/3 + 1/6 = (4/6) + (1/6) = 5/6

Therefore, the sum of -1 2/3 and 4 1/6 is 3 5/6.