diff --git a/Klassen.py b/Klassen.py
index bc9abf9..64c0d25 100644
--- a/Klassen.py
+++ b/Klassen.py
@@ -101,6 +101,8 @@ class Formel:
     def solve(self, ges):
         if 'i' == ges.equals_var:
             self.solver._solve_to_i()
+        elif 'e' == ges.equals_var:
+            self.solver._solve_to_e()
         elif 'c' == ges.equals_var:
             self.solver._solve_to_c()
         elif 'b' == ges.equals_var: