final price calculating fixed

apps/course/models/course.py

@@ -523,15 +523,15 @@ class Course(models.Model):
             self.final_price = Decimal('0.00')
             self.final_price_rub = Decimal('0.00')
         elif self.discount_percentage > 0:
-            usd_discount_amount = (usd_price * self.discount_percentage) / 100
-            rub_discount_amount = (rub_price * self.discount_percentage) / 100
+            usd_discount_amount = (usd_price * Decimal(self.discount_percentage)) / Decimal('100')
+            rub_discount_amount = (rub_price * Decimal(self.discount_percentage)) / Decimal('100')
             usd_final_price = usd_price - usd_discount_amount
             rub_final_price = rub_price - rub_discount_amount
-            self.final_price = Decimal(math.ceil(usd_final_price)).quantize(Decimal('0.00'))
-            self.final_price_rub = Decimal(math.ceil(rub_final_price)).quantize(Decimal('0.00'))
+            self.final_price = usd_final_price.quantize(Decimal('0.00'))
+            self.final_price_rub = rub_final_price.quantize(Decimal('0.00'))
         else:
-            self.final_price = Decimal(math.ceil(usd_price)).quantize(Decimal('0.00'))
-            self.final_price_rub = Decimal(math.ceil(rub_price)).quantize(Decimal('0.00'))
+            self.final_price = usd_price.quantize(Decimal('0.00'))
+            self.final_price_rub = rub_price.quantize(Decimal('0.00'))
 
         super().save(*args, **kwargs)