Quotient of 6 and 9 is 6/9 which cancels down to ⅔ when we divide top and bottom by the common factor 3. Now we have to subtract this quotient from 8 so we have 8-⅔. We can make this look a bit simpler:
7+1-⅔, and when we take ⅔ from 1 we are left with ⅓ because three thirds make 1 and 3 take away 2 leaves us with 1. So we have 7+⅓ which is written 7⅓.