Answer:
5/6 or 0.83333
Explanation:
Add: 9/18 + 1/3 = 9/18 + 1 · 6/3 · 6 = 9/18 + 6/18= 9 + 6/18= 15/18= 3 · 5/3 · 6= 5/6 or 0.83333
The common denominator you can calculate as the least common multiple of the both denominators - LCM(18, 3) = 18. Cancelling by a common factor of 3 gives 5/6 or 0.83333
In words - nine eighteenths plus one third = five sixths.