99 is h fewer than 88
Translating from the English language to mathematical language is a critical skill.
Keep these things in mind. "Is" translates as "=". When you see "fewer," you are dealing with subtraction.
99 = 88 – h
The above is the mathematical translation. To solve it. You subtract 88 from each side to get: 11 = –h.
Then you divide the new equation by –1 to get: h = –11.
This is a bit hard to wrap your head around since a "negative number fewer" is not intuitive. The good news is that, as long as you do the translation correctly, solving the problem is relatively easy.