diff --git a/advlabdb/models.py b/advlabdb/models.py
index 3c9086b..8cfc3b5 100644
--- a/advlabdb/models.py
+++ b/advlabdb/models.py
@@ -210,6 +210,21 @@ class Experiment(db.Model):
 
     __table_args__ = (db.UniqueConstraint(number, program_id),)
 
+    def checkWeightings(self, roundWeightings=False):
+        roundedOralWeighting = round(self.oral_weighting, 2)
+        roundedProtocolWeighting = round(self.protocol_weighting, 2)
+
+        weightingSum = round(roundedOralWeighting + roundedProtocolWeighting, 2)
+
+        if weightingSum != 1:
+            raise DataBaseException(
+                f"Oral and protocol weighting (rounded to 2 decimal digits) sum to {weightingSum} and not 1.00!"
+            )
+
+        if roundWeightings:
+            self.oral_weighting = roundedOralWeighting
+            self.protocol_weighting = roundedProtocolWeighting
+
     def repr(self):
         return f"{self.number} {self.program.repr()}"
 
@@ -381,10 +396,18 @@ class ExperimentMark(db.Model):
     id = db.Column(db.Integer, primary_key=True)
 
     oral_mark = db.Column(
-        db.Integer, db.CheckConstraint("oral_mark > -1"), db.CheckConstraint("oral_mark < 16"), nullable=True
+        db.Integer,
+        db.CheckConstraint("oral_mark > -1"),
+        db.CheckConstraint("oral_mark < 16"),
+        default=0.5,
+        nullable=True,
     )
     protocol_mark = db.Column(
-        db.Integer, db.CheckConstraint("protocol_mark > -1"), db.CheckConstraint("protocol_mark < 16"), nullable=True
+        db.Integer,
+        db.CheckConstraint("protocol_mark > -1"),
+        db.CheckConstraint("protocol_mark < 16"),
+        default=0.5,
+        nullable=True,
     )
 
     edited_by_admin = db.Column(db.Boolean, default=False, nullable=False)