diff --git a/accounting/api/account.py b/accounting/api/account.py
index e843e61..33bbdd2 100644
--- a/accounting/api/account.py
+++ b/accounting/api/account.py
@@ -1,7 +1,7 @@
 from ninja import Router
 from ninja.security import django_auth
 from django.shortcuts import get_object_or_404
-from accounting.models import Account, AccountTypeChoices
+from accounting.models import Account, AccountTypeChoices , JournalEntry
 from accounting.schemas import AccountOut, FourOFourOut, GeneralLedgerOut
 from typing import List
 from django.db.models import Sum, Avg
@@ -51,7 +51,7 @@ def get_account_balances(request):
     result = []
     for a in accounts:
         result.append({
-            'account': a.name, 'balance': list(a.balance())
+            'account': a.name, 'balance': list(a.sumbalance())
         })
 
     return status.HTTP_200_OK, result
@@ -59,29 +59,4 @@ def get_account_balances(request):
 
 
 
-class Balance:
-    def __init__(self, balances):
-        balance1 = balances[0]
-        balance2 = balances[1]
-
-        if balance1['currency'] == 'USD':
-            balanceUSD = balance1['sum']
-            balanceIQD = balance2['sum']
-        else:
-            balanceIQD = balance1['sum']
-            balanceUSD = balance2['sum']
-
-        self.balanceUSD = balanceUSD
-        self.balanceIQD = balanceIQD
-
-    def __add__(self, other):
-        self.balanceIQD += other.balanceIQD
-        self.balanceUSD += other.balanceUSD
-        return [{
-            'currency': 'USD',
-            'sum': self.balanceUSD
-        }, {
-            'currency': 'IQD',
-            'sum': self.balanceIQD
-        }]
 
diff --git a/accounting/models.py b/accounting/models.py
index a7d49b7..00a1173 100644
--- a/accounting/models.py
+++ b/accounting/models.py
@@ -3,6 +3,7 @@
 from django.dispatch import receiver
 from django.db.models.signals import post_save
 from accounting.exceptions import AccountingEquationError
+from accounting.api import Balance
 
 '''
 
@@ -27,7 +28,70 @@
 * Each Transaction should consist of two or more even numbered Journal Entries
 
 '''
+class Balance:
+    def __init__(self, balances):
+        balanceIQD = 0
+        balanceUSD = 0
+        for i in balances:
+            if i['currency'] == 'USD':
+                balanceUSD = i['sum']
+            if i['currency'] == 'IQD':
+                balanceIQD = i['sum']
+
+        self.balanceUSD = balanceUSD
+        self.balanceIQD = balanceIQD
+
+    def __add__(self, other):
+        self.balanceIQD += other.balanceIQD
+        self.balanceUSD += other.balanceUSD
+        return [{
+            'currency': 'USD',
+            'sum': self.balanceUSD
+        }, {
+            'currency': 'IQD',
+            'sum': self.balanceIQD
+        }]
+
+
+    def __radd__(self,other):
+        if other == 0:
+            return self
+        else:
+            return self.__add__(other)
+        
+            #TASK4 function1
+    def __greatThan__ (self, other):
+        if self.balanceIQD > other.balanceIQD:
+            IQD = True
+        else:
+            IQD = False
+        if self.balanceUSD > other.balanceUSD:
+            USD = True
+        else:
+            USD = False
+        return {'IQD': IQD, 'USD': USD}
+
+             #function2
+    def __lessThan__ (self, other):
+        if self.balanceIQD < other.balanceIQD:
+            IQD = True
+        else:
+            IQD = False
+        if self.balanceUSD < other.balanceUSD:
+            USD = True
+        else:
+            USD = False
+        return {'IQD': IQD, 'USD': USD}   
+    
+    
+    #function3
+    def __iszero__(self):
 
+        if self.balanceIQD == 0 and self.balanceUSD==0:
+            return True
+        else:
+            return False     
+    
 
 class AccountTypeChoices(models.TextChoices):
     ASSETS = 'ASSETS', 'Assets'
@@ -49,7 +113,7 @@ class CurrencyChoices(models.TextChoices):
 
 
 class Account(models.Model):
-    parent = models.ForeignKey('self', null=True, blank=True, on_delete=models.SET_NULL)
+    parent = models.ForeignKey('self', null=True, blank=True, on_delete=models.SET_NULL, related_name='account_children')
     type = models.CharField(max_length=255, choices=AccountTypeChoices.choices)
     name = models.CharField(max_length=255)
     code = models.CharField(max_length=20, null=True, blank=True)
@@ -61,6 +125,27 @@ def __str__(self):
 
     def balance(self):
         return self.journal_entries.values('currency').annotate(sum=Sum('amount')).order_by()
+    
+    
+    
+      
+    def sumbalance(self):
+
+        if self.parent is not None:
+            return self.balance()
+        else:
+            children = self.account_children.all()
+            if len(children) == 1:
+                return self.balance()
+            elif len(children) == 0:
+                return self.balance()
+            else:
+                sum_balance = []
+            for childrens in list(children):
+                child_Balance = childrens.sumbalance()
+                sum_balance.append(Balance(child_Balance))
+
+            return sum(sum_balance)
 
     # def save(
     #         self, force_insert=False, force_update=False, using=None, update_fields=None