Suppose in a given class you have a daily grade of 92, exam 1 grade of 85, exam 2 grade of 87, and a final exam grade of 93. IF the daily grade counts 10 percent, the first two exams count 25 percent each and the final counts 40 percent then your final grade would be
\begin{equation*}
\frac{0.10 \cdot 92 + 0.25 \cdot 85 + 0.25 \cdot 87 + 0.40 \cdot 0.93}{0.10 + 0.25 + 0.25 + 0.40} = 89.4 .
\end{equation*}
It would then appear that you might want to do some bargaining with your teacher about how nice it would be to round that up.