diff --git a/CHANGELOG b/CHANGELOG
index 0aacdd1..37b70e5 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,6 @@
 Version 0.7.1 (2007.02.27):
-	* fixed the error 'overflow during printing' which was caused by Big::FromInt(Int<int_size> value)
-	  (the sign has to be set at the end)
+	* fixed the error 'overflow during printing' which was caused
+	  by Big::FromInt(Int<int_size> value) (the sign has to be set at the end)
 	* fixed many small errors
 	* added ATan (arctan), ACTan (arc ctan) functions
 
diff --git a/TODO b/TODO
index f7e18ca..ebf3cc1 100644
--- a/TODO
+++ b/TODO
@@ -1,7 +1,7 @@
 TODO TTMath Library
 ===================
 
-* to add the method Mod (a remainder from a division) for the Big type
 * to add operators (or functions) and, or, xor
 * to add functions for generating random values
 * to add constructors (UInt, Int) for 64bit platforms (constractors which take int and unsigned)
+* to add 'history' for functions like 'factorial' which take a lot of time during calculating
diff --git a/ttmath/ttmath.h b/ttmath/ttmath.h
index 38db0dd..66c392c 100644
--- a/ttmath/ttmath.h
+++ b/ttmath/ttmath.h
@@ -133,7 +133,40 @@ namespace ttmath
 	return result;
 	}
 
-	
+
+
+	/*!
+		it returns the sign of the value
+		e.g.  -2 = 1 
+		       0 = 0
+		      10 = 1
+	*/
+	template<class ValueType>
+	ValueType Sgn(ValueType x)
+	{
+		x.Sgn();
+
+	return x;
+	}
+
+
+	/*!
+		the remainder from the division
+
+		e.g.
+		mod( 12.6 ;  3) =  0.6   because 12.6 = 3*4 + 0.6
+		mod(-12.6 ;  3) = -0.6
+		mod( 12.6 ; -3) =  0.6
+		mod(-12.6 ; -3) = -0.6
+	*/
+	template<class ValueType>
+	ValueType Mod(ValueType a, const ValueType & b)
+	{
+		a.Mod(b);
+
+	return a;
+	}
+
 	/*!
 		this method skips the fraction from x
 		e.g  2.2  = 2
diff --git a/ttmath/ttmathbig.h b/ttmath/ttmathbig.h
index 6eadebd..79ba286 100644
--- a/ttmath/ttmathbig.h
+++ b/ttmath/ttmathbig.h
@@ -348,6 +348,28 @@ public:
 	}
 
 
+	/*!
+		it remains the 'sign' of the value
+		e.g.  -2 = 1 
+		       0 = 0
+		      10 = 1
+	*/
+	void Sgn()
+	{
+		if( IsSign() )
+		{
+			SetOne();
+			SetSign();
+		}
+		else
+		if( IsZero() )
+			SetZero();
+		else
+			SetOne();
+	}
+
+
+
 	/*!
 		it sets the sign
 
@@ -569,6 +591,36 @@ public:
 	}
 
 
+	/*!
+		the remainder from the division
+
+		e.g.
+		 12.6 mod  3 =  0.6   because 12.6 = 3*4 + 0.6
+		-12.6 mod  3 = -0.6
+		 12.6 mod -3 =  0.6
+		-12.6 mod -3 = -0.6
+
+		it means:
+		in other words: this(old) = ss2 * q + this(new)(result)
+	*/
+	uint Mod(const Big<exp, man> & ss2)
+	{
+	TTMATH_REFERENCE_ASSERT( ss2 )
+
+	uint c = 0;
+
+		Big<exp, man> temp(*this);
+
+		c += temp.Div(ss2);
+		temp.SkipFraction();
+		c += temp.Mul(ss2);
+		c += Sub(temp);
+
+	return (c==0)? 0 : 1;
+	}
+
+
+
 	/*!
 		power this = this ^ pow
 		pow without a sign
diff --git a/ttmath/ttmathparser.h b/ttmath/ttmathparser.h
index 7cf02b8..362b66d 100644
--- a/ttmath/ttmathparser.h
+++ b/ttmath/ttmathparser.h
@@ -748,6 +748,32 @@ void ACTan(int sindex, int amount_of_args, ValueType & result)
 }
 
 
+void Sgn(int sindex, int amount_of_args, ValueType & result)
+{
+	if( amount_of_args != 1 )
+		Error( err_improper_amount_of_arguments );
+
+	result = ttmath::Sgn(stack[sindex].value);
+}
+
+
+void Mod(int sindex, int amount_of_args, ValueType & result)
+{
+	if( amount_of_args != 2 )
+		Error( err_improper_amount_of_arguments );
+
+	if( stack[sindex+2].value.IsZero() )
+		Error( err_improper_argument );
+
+	result = stack[sindex].value;
+	uint c = result.Mod(stack[sindex+2].value);
+
+	if( c )
+		Error( err_overflow );
+}
+
+
+
 /*!
 	this method returns the value from a user-defined function
 
@@ -874,6 +900,8 @@ void CreateFunctionsTable()
 	InsertFunctionToTable(std::string("acos"),   	&Parser<ValueType>::ACos);
 	InsertFunctionToTable(std::string("atan"),   	&Parser<ValueType>::ATan);
 	InsertFunctionToTable(std::string("actan"),   	&Parser<ValueType>::ACTan);
+	InsertFunctionToTable(std::string("sgn"),   	&Parser<ValueType>::Sgn);
+	InsertFunctionToTable(std::string("mod"),   	&Parser<ValueType>::Mod);
 }
 
 
@@ -1728,8 +1756,6 @@ ErrorCode Parse(const char * str)
 	
 	stack.resize( default_stack_size );
 
-//	char buf_temp[] = "-(1)";
-//	pstring = buf_temp;
 
 	try
 	{