What is the estimate and answer for 8- 6 1/9

Easy, do the same thing here,

change the numbers into whole numbers to be able to estimate:

8 >8
and
6 1/9---> 6
( 6 1/9 changes into 6, because 1/9 is not big enough to change into 9/9 making 6 1/9---> 7)

8-6=2

2 is your estimate.

8
-
6 1/9

change 8 into > 7 9/9 to be able to subtract

7 9/9
-
6 1/9
=

1 8/9

Thus, your answers are, 2 and 1 8/9.