diff --git a/app.py b/app.py
index e7aa139..6f847b8 100644
--- a/app.py
+++ b/app.py
@@ -43,16 +43,25 @@ def index():
         else:
             count = len(alle)
 
-        for i in range(1,count):
+        while count > 1:
             if len(alle) == 0:
                 break
             term = alle.pop(random.randint(0,len(alle)-1))
             term.c = ''
             if request.form.get('gemischteAufgaben'):
                 maxValue = eval(str(term.a) + term.t.typ + str(term.b))
-                term.c += ' + ' if random.randint(0,1) else ' - '
+                if random.randint(0,1):
+                    term.c += ' + '
+                    t = int(100 - maxValue)
+                    maxValue = t
+                else:
+                    term.c += ' - '
+                if maxValue <= 1:
+                    alle.append(term)
+                    continue
                 term.c += str(random.randint(1,maxValue))
             zufall.append(term)
+            count -= 1
         return render_template('arbeitsblatt.html',aufgaben=zufall,maxPerPage=int(request.form.get('maxPerPage')))
     else:
         return render_template('generator.html', reihen=rt_rechenreihen)
diff --git a/templates/generator.html b/templates/generator.html
index 01638d3..e99c064 100644
--- a/templates/generator.html
+++ b/templates/generator.html
@@ -28,12 +28,12 @@
         <br/>
         <label for="anzahl">max. Aufgaben: </label>
         <select name="anzahl">
-            <option value="">Alle</option>
             <option value="78">78</option>
             <option value="39">39</option>
+            <option value="">Alle</option>
         </select><br/>
         <label for="maxPerPage">max. Aufgaben pro Seite</label>
-        <input name="maxPerPage" value="78"><br/>
+        <input name="maxPerPage" value="39"><br/>
         <br/>
         <input type="submit" value="zum Arbeitsblatt">
     </form>