diff --git a/mapytex/calculus/API/tokens/__init__.py b/mapytex/calculus/API/tokens/__init__.py
index 2a0b4dd..d9a6b43 100644
--- a/mapytex/calculus/API/tokens/__init__.py
+++ b/mapytex/calculus/API/tokens/__init__.py
@@ -60,16 +60,16 @@ def factory(exp, name="", ancestor=None):
 
     if isinstance(mo, MOnumber):
         if isinstance(mo.value, int):
-            return Integer(mo, name, ancestor)
+            return Integer.from_mo(mo, name, ancestor)
         elif isinstance(mo.value, _Decimal):
-            return Decimal(mo, name, ancestor)
+            return Decimal.from_mo(mo, name, ancestor)
 
         raise TypeError(f"Can't build from MOnumber ({mo}) neither int nor decimal")
 
     elif isinstance(mo, MOFraction):
         if isinstance(mo._denominator, MOnumber) and \
                 isinstance(mo._numerator, MOnumber):
-            return Fraction(mo, name, ancestor)
+            return Fraction.from_mo(mo, name, ancestor)
 
         raise TypeError(f"Can't build from MOFraction ({mo}) numerator and denominator are not MOnumber")
 
@@ -79,13 +79,13 @@ def factory(exp, name="", ancestor=None):
         if isinstance(mo, MOstr) or \
                 (isinstance(mo, MOMonomial) and mo.power.value == 1) or \
                 (isinstance(mo, MOpolynomial) and mo.power.value == 1):
-            return Linear(mo, name, ancestor)
+            return Linear.from_mo(mo, name, ancestor)
         elif (isinstance(mo, MOstrPower) and  mo.power.value == 2) or \
             (isinstance(mo, MOMonomial) and mo.power.value == 2) or \
             (isinstance(mo, MOpolynomial) and mo.power.value == 2):
-            return Quadratic(mo, name, ancestor)
+            return Quadratic.from_mo(mo, name, ancestor)
         else:
-            return Polynomial(mo, name, ancestor)
+            return Polynomial.from_mo(mo, name, ancestor)
 
     else:
         raise TypeError(f"{type(mo)} is unknown MathObject")
diff --git a/mapytex/calculus/API/tokens/number.py b/mapytex/calculus/API/tokens/number.py
index 608cd4a..e8e7b88 100644
--- a/mapytex/calculus/API/tokens/number.py
+++ b/mapytex/calculus/API/tokens/number.py
@@ -11,6 +11,7 @@ Tokens representing interger and decimal
 
 """
 from .token import Token
+from ...core.MO import MO
 from ...core.MO.mo import MOnumber
 from ...core.MO.fraction import MOFraction
 from decimal import Decimal as _Decimal
@@ -19,17 +20,37 @@ __all__ = ["Integer", "Decimal"]
 
 class Integer(Token):
 
-    """ Token representing a integer """
+    """ Token representing a integer 
+    
+    :example:
+    >>> Integer(4)
+    <Integer 4>
+    >>> a = MOnumber(4)
+    >>> Integer.from_mo(a)
+    <Integer 4>
+    
+    """
 
-    def __init__(self, mo, name="", ancestor=None):
-        if not isinstance(mo, MOnumber):
-            raise TypeError
-        if  not isinstance(mo.value, int):
-            raise TypeError
+    def __init__(self, a, name="", ancestor=None):
+        if not isinstance(a, MO):
+            if not isinstance(a, int):
+                raise TypeError
+            mo = MOnumber(a)
+        else:
+            mo = a
 
         Token.__init__(self, mo, name, ancestor)
         self._mathtype = 'entier'
 
+    @classmethod
+    def from_mo(cls, mo, name="", ancestor=None):
+        if not isinstance(mo, MOnumber):
+            raise TypeError
+        if not isinstance(mo.value, int):
+            raise TypeError
+
+        return cls(mo, name, ancestor)
+
     @classmethod
     def random(cls):
         raise NotImplemented
@@ -38,14 +59,26 @@ class Decimal(Token):
 
     """ Token representing a decimal """
 
-    def __init__(self, mo, name="", ancestor=None):
+    def __init__(self, a, name="", ancestor=None):
+        if not isinstance(a, MO):
+            if isinstance(a, (str, float)):
+                mo = MOnumber(Decimal(a))
+            else:
+                raise TypeError
+        else:
+            mo = a
+
+        self._mathtype = 'décimal'
+        Token.__init__(self, mo, name, ancestor)
+
+    @classmethod
+    def from_mo(cls, mo, name="", ancestor=None):
         if not isinstance(mo, MOnumber):
             raise TypeError
         if  not isinstance(mo.value, _Decimal):
             raise TypeError
 
-        Token.__init__(self, mo, name, ancestor)
-        self._mathtype = 'décimal'
+        return cls(mo, name, ancestor)
 
     @classmethod
     def random(cls):
@@ -55,7 +88,21 @@ class Fraction(Token):
 
     """ Token representing a fraction """
 
-    def __init__(self, mo, name="", ancestor=None):
+    def __init__(self, a, name="", ancestor=None):
+        if not isinstance(a, MO):
+            if isinstance(a, str):
+                num, denom = a.split('/')
+                mo = MOFraction(num, denom)
+            else:
+                raise TypeError
+        else:
+            mo = a
+
+        self._mathtype = 'fraction'
+        Token.__init__(self, mo, name, ancestor)
+
+    @classmethod
+    def from_mo(cls, mo, name="", ancestor=None):
         if not isinstance(mo, MOFraction):
             raise TypeError
         if  not isinstance(mo._numerator, MOnumber):
@@ -63,8 +110,7 @@ class Fraction(Token):
         if  not isinstance(mo._denominator, MOnumber):
             raise TypeError
 
-        Token.__init__(self, mo, name, ancestor)
-        self._mathtype = 'fraction'
+        return cls(mo, name, ancestor)
 
     @classmethod
     def random(cls):
diff --git a/mapytex/calculus/API/tokens/polynomial.py b/mapytex/calculus/API/tokens/polynomial.py
index d93ba71..36e10fa 100644
--- a/mapytex/calculus/API/tokens/polynomial.py
+++ b/mapytex/calculus/API/tokens/polynomial.py
@@ -11,6 +11,7 @@ Tokens representing polynomials functions
 
 """
 from .token import Token
+from ...core.MO import MO
 
 __all__ = ["Polynomial", "Quadratic", "Linear"]
 
@@ -18,11 +19,23 @@ class Polynomial(Token):
 
     """ Token representing a polynomial """
 
-    def __init__(self, mo, name="", ancestor=None):
+    def __init__(self, a, name="", ancestor=None):
+        if not isinstance(a, MO):
+            if isinstance(a, str):
+                raise TypeError
+            else:
+                raise TypeError
+        else:
+            mo = a
 
         Token.__init__(self, mo, name, ancestor)
         self._mathtype = 'polynome'
 
+    @classmethod
+    def from_mo(cls, mo, name="", ancestor=None):
+
+        return cls(mo, name, ancestor)
+
     @classmethod
     def random(cls):
         raise NotImplemented
@@ -39,26 +52,26 @@ class Polynomial(Token):
         """ Call a Polynomial to evaluate itself on value """
         pass
 
-class Linear(Token):
+class Linear(Polynomial):
 
     """ Token representing a linear """
 
     def __init__(self, mo, name="", ancestor=None):
 
-        Token.__init__(self, mo, name, ancestor)
+        Polynomial.__init__(self, mo, name, ancestor)
         self._mathtype = 'affine'
 
     @classmethod
     def random(cls):
         raise NotImplemented
 
-class Quadratic(Token):
+class Quadratic(Polynomial):
 
     """ Token representing a quadratic """
 
     def __init__(self, mo, name="", ancestor=None):
 
-        Token.__init__(self, mo, name, ancestor)
+        Polynomial.__init__(self, mo, name, ancestor)
         self._mathtype = 'polynome du 2nd degré'
 
     @classmethod
diff --git a/mapytex/calculus/API/tokens/token.py b/mapytex/calculus/API/tokens/token.py
index 9aa481b..637c3fe 100644
--- a/mapytex/calculus/API/tokens/token.py
+++ b/mapytex/calculus/API/tokens/token.py
@@ -63,6 +63,25 @@ class Token(object):
     def __tex__(self):
         return self._mo.__tex__
 
+    def __add__(self, other):
+        """ Adding 2 Tokens or a Token and a Expression
+
+        :example:
+        >>> from .number import Integer 
+        >>> a = Integer(3)
+
+        """
+        from ..expression import Expression
+        from ...core import Tree
+        from . import factory
+        if not isinstance(other, Token):
+            _other = factory(other)
+        else:
+            _other = other
+        tree = Tree('+', self.mo, _other.mo)
+        ans = Expression(tree).simplify()
+        return ans
+