diff --git a/BUGS.md b/BUGS.md
index 639e50a..8b55138 100644
--- a/BUGS.md
+++ b/BUGS.md
@@ -1,6 +1,7 @@
 
 # BUGS
 
+- change password modal nao aparece no ipad (safari e firefox)
 - on start topic, logs show questionhandler.get() twice.
 - generators e correct scripts que durem muito tempo podem bloquear o loop do tornado?
 - detect questions in questions.yaml without ref -> error ou generate default.
@@ -29,6 +30,7 @@
 
 # FIXED
 
+- numero de estrelas depende da proporcao entre certas e erradas.
 - image brand da universidade está esbatida.
 - reportar comentarios após submeter.
 - error if demo.yaml has no topics
diff --git a/knowledge.py b/knowledge.py
index 2399ce2..6de2ea1 100644
--- a/knowledge.py
+++ b/knowledge.py
@@ -89,6 +89,8 @@ class StudentKnowledge(object):
         factory = self.deps.node[topic]['factory']
         questionlist = self.deps.node[topic]['questions']
 
+        self.correct_answers = 0
+        self.wrong_answers = 0
         self.finished_questions = []
         self.questions = [factory[qref].generate() for qref in questionlist]
         logger.debug(f'Total: {len(self.questions)} questions')
@@ -113,9 +115,9 @@ class StudentKnowledge(object):
 
         self.current_question = None
         self.state[self.current_topic] = {
-            'level': 1.0,
-            'date': datetime.now()
-        }
+            'date': datetime.now(),
+            'level': self.correct_answers / (self.correct_answers + self.wrong_answers)
+            }
         self.unlock_topics()
 
 
@@ -134,6 +136,7 @@ class StudentKnowledge(object):
 
         # if answer is correct, get next question
         if grade > 0.999:
+            self.correct_answers += 1
             self.finished_questions.append(q)
             try:
                 self.current_question = self.questions.pop(0) # FIXME empty?
@@ -144,6 +147,7 @@ class StudentKnowledge(object):
 
         # if answer is wrong, keep same question and add a similar one at the end
         else:
+            self.wrong_answers += 1
             factory = self.deps.node[self.current_topic]['factory']
             self.questions.append(factory[q['ref']].generate())
 
diff --git a/templates/maintopics.html b/templates/maintopics.html
index b4d52a6..987acd5 100644
--- a/templates/maintopics.html
+++ b/templates/maintopics.html
@@ -88,9 +88,9 @@
                 {% if t['type']=='chapter' %}
                   <i class="fas fa-trophy fa-lg text-warning"></i>
                 {% else %}
-                <span class="text-nowrap">
-                  {{ round(t['level']*5)*'<i class="fas fa-star text-warning"></i>' + round(5-t['level']*5)*'<i class="far fa-star text-warning"></i>' }}
-                </span>
+                  <span class="text-nowrap">
+                  {{ round(t['level']*5)*'<i class="fas fa-star text-warning"></i>' + (5-round(t['level']*5))*'<i class="far fa-star text-warning"></i>' }}
+                  </span>
                 {% end %}
               {% end %}
             </div>
--
libgit2 0.21.2