diff --git a/src/rpn-cmd.h b/src/rpn-cmd.h
index abf966b..49dcb09 100644
--- a/src/rpn-cmd.h
+++ b/src/rpn-cmd.h
@@ -33,9 +33,9 @@ program::keyword_t program::_keywords[] =
 
     //REAL representation
     { cmd_undef, "", NULL, "\nREAL REPRESENTATION"},
-    //{ cmd_keyword, "dec", &program::dec, "decimal representation" },
-    //{ cmd_keyword, "hex", &program::hex, "hexadecimal representation" },
-    //{ cmd_keyword, "bin", &program::bin, "binary representation" },
+    { cmd_keyword, "dec", &program::dec, "decimal representation" },
+    { cmd_keyword, "hex", &program::hex, "hexadecimal representation" },
+    { cmd_keyword, "bin", &program::bin, "binary representation" },
     { cmd_keyword, "std", &program::std, "standard floating numbers representation. ex: [25] std" },
     { cmd_keyword, "fix", &program::fix, "fixed point representation. ex: 6 fix" },
     { cmd_keyword, "sci", &program::sci, "scientific floating point representation. ex: 20 sci" },
diff --git a/src/rpn-real.h b/src/rpn-real.h
index 369660d..7969005 100644
--- a/src/rpn-real.h
+++ b/src/rpn-real.h
@@ -126,3 +126,24 @@ void modulo()
 
     CHECK_MPFR(mpfr_fmod(left->_value.mpfr, left->_value.mpfr, right->_value.mpfr, s_mpfr_rnd));
 }
+
+void hex()
+{
+    MIN_ARGUMENTS(1);
+    ARG_MUST_BE_OF_TYPE(0, cmd_number);
+    ((number*)_stack->back())->_representation = number::hex;
+}
+
+void bin()
+{
+    MIN_ARGUMENTS(1);
+    ARG_MUST_BE_OF_TYPE(0, cmd_number);
+    ((number*)_stack->back())->_representation = number::bin;
+}
+
+void dec()
+{
+    MIN_ARGUMENTS(1);
+    ARG_MUST_BE_OF_TYPE(0, cmd_number);
+    ((number*)_stack->back())->_representation = number::dec;
+}
diff --git a/src/rpn.cpp b/src/rpn.cpp
index 140b78b..a76cd4e 100644
--- a/src/rpn.cpp
+++ b/src/rpn.cpp
@@ -48,12 +48,11 @@ using namespace std;
 #define MPFR_128BITS_PREC 128
 #define MPFR_128BITS_STORING_LENGTH 16
 
-static string s_mpfr_printf_format_hex = "0x";
-static string s_mpfr_printf_format_bin = "0b";
 static string s_mpfr_printf_format_beg = "%.";
 static string s_mpfr_printf_format_std = "Rg";
 static string s_mpfr_printf_format_fix = "Rf";
 static string s_mpfr_printf_format_sci = "Re";
+static string s_mpfr_printf_format_hex = "%Ra";
 static string s_mpfr_printf_format = "%.12Rg";
 static mpfr_prec_t s_mpfr_prec = MPFR_128BITS_PREC;
 static mpfr_rnd_t s_mpfr_rnd = MPFR_DEF_RND;
@@ -373,8 +372,19 @@ void object::show(ostream& stream)
     switch(_type)
     {
     case cmd_number:
-        (void)mpfr_sprintf(buffer, s_mpfr_printf_format.c_str(), ((number*)this)->_value.mpfr);
-        stream<<buffer;
+        switch(((number*)this)->_representation)
+        {
+            case number::dec:
+                (void)mpfr_sprintf(buffer, s_mpfr_printf_format.c_str(), ((number*)this)->_value.mpfr);
+                stream<<buffer;
+                break;
+            case number::hex:
+                (void)mpfr_sprintf(buffer, s_mpfr_printf_format_hex.c_str(), ((number*)this)->_value.mpfr);                
+                stream<<buffer;
+                break;
+            case number::bin:
+                cout<<"<binary representation TODO>";
+        }
         break;
     case cmd_string:
         stream << "\"" << ((ostring*)this)->_value << "\"";