diff --git a/CHANGELOG b/CHANGELOG
index 6b87cf8..09f1194 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,4 +1,4 @@
-Version 0.9.0 prerelease (2009.10.03):
+Version 0.9.0 prerelease (2009.10.13):
     * fixed:   Big::operator>>(std::istream&, Big<> &) didn't recognize values
                in scientific mode (with 'e' character)
     * fixed:   UInt::SetBitInWord(uint & value, uint bit) set 1 if the bit was 
@@ -32,6 +32,9 @@ Version 0.9.0 prerelease (2009.10.03):
     * added:   macro: TTMATH_BITS(min_bits)
 		       which returns the number of machine words 
 		       capable to hold min_bits bits
+    * added:   bool Parser::Calculated()
+               this method returns true is something was calculated
+               (at least one mathematical operator was used or a function or variable)
     * changed: Factorial() is using the Gamma() function now
     * changed: Big::Div(ss2)
                Big::Mod(ss2)
diff --git a/ttmath/ttmathparser.h b/ttmath/ttmathparser.h
index 9e98398..0acd575 100644
--- a/ttmath/ttmathparser.h
+++ b/ttmath/ttmathparser.h
@@ -438,6 +438,11 @@ CGamma<ValueType> cgamma;
 std::string wide_to_ansi;
 
 
+/*!
+	true if something was calculated (at least one mathematical operator was used or a function or a variable)
+*/
+bool calculated;
+
 /*!
 	we're using this method for reporting an error
 */
@@ -566,6 +571,7 @@ bool GetValueOfUserDefinedVariable(const std::string & variable_name,ValueType &
 		return false;
 
 	result = RecurrenceParsingVariablesOrFunction(true, variable_name, string_value);
+	calculated = true;
 
 return true;
 }
@@ -614,6 +620,7 @@ ValueType result;
 		Error( err_unknown_variable );
 
 	(result.*(i->second))();
+	calculated = true;
 
 return result;
 }
@@ -1432,6 +1439,7 @@ bool GetValueOfUserDefinedFunction(const std::string & function_name, int amount
 	}
 
 	stack[sindex-1].value = RecurrenceParsingVariablesOrFunction(false, function_name, string_value, &local_variables);
+	calculated = true;
 
 return true;
 }
@@ -1464,6 +1472,7 @@ void CallFunction(const std::string & function_name, int amount_of_args, int sin
 		calling the specify function
 	*/
 	(this->*(i->second))(sindex, amount_of_args, stack[sindex-1].value);
+	calculated = true;
 }
 
 
@@ -1983,6 +1992,8 @@ void MakeStandardMathematicOperation(ValueType & value1, typename MatOperator::T
 {
 uint res;
 
+	calculated = true;
+
 	switch( mat_operator )
 	{
 	case MatOperator::land:
@@ -2540,7 +2551,8 @@ ErrorCode Parse(const char * str)
 	stack_index  = 0;
 	pstring      = str;
 	error        = err_ok;
-	
+	calculated   = false;
+
 	stack.resize( default_stack_size );
 
 	try
@@ -2550,6 +2562,7 @@ ErrorCode Parse(const char * str)
 	catch(ErrorCode c)
 	{
 		error = c;
+		calculated = false;
 	}
 
 	NormalizeStack();
@@ -2587,6 +2600,21 @@ ErrorCode Parse(const std::wstring & str)
 }
 
 
+/*!
+	this method returns true is something was calculated
+	(at least one mathematical operator was used or a function or variable)
+	e.g. the string to Parse() looked like this:
+	"1+1"
+	"2*3"
+	"sin(5)"
+
+	if the string was e.g. "678" the result is false
+*/
+bool Calculated()
+{
+	return calculated;
+}
+
 };