1 7/9 ÷ 2

(  1 + 7/9) / 2  =

(16/9) / ( 2 / 1)  =      invert the fraction in the denominator and multiply

(16 / 9)  * ( 1 / 2)  =  rearrange  as

(16 / 2) * ( 1 / 9)  =

16 / 18  =

8 / 9