Index: scalc/lib/subgroups.cc
===================================================================
--- scalc.orig/lib/subgroups.cc
+++ scalc/lib/subgroups.cc
@@ -32,7 +32,7 @@ namespace SCalc {
     Expression * s = sub->simplify();
     if(s->is_const())
       {
-	double val = sub->evaluate(NULL, NULL);
+	double val = s->evaluate(NULL, NULL);
 	delete s;
 	return new Const(session(), val);
       }