Step 1: Understanding the magnification formula.
The total magnification \( M_{\text{total}} \) of a compound microscope is the product of the objective magnification and the eyepiece magnification:
\[
M_{\text{total}} = M_{\text{objective}} \times M_{\text{eyepiece}}.
\]
Step 2: Substituting the known values.
We are given that \( M_{\text{total}} = 100 \) and \( M_{\text{objective}} = 10 \).
\[
100 = 10 \times M_{\text{eyepiece}},
\]
\[
M_{\text{eyepiece}} = 10.
\]
Step 3: Conclusion.
The angular magnification of the eyepiece should be \( \boxed{10} \).