Index: Lib/decimal.py
===================================================================
--- Lib/decimal.py	(revision 59523)
+++ Lib/decimal.py	(working copy)
@@ -1454,6 +1454,10 @@
 
     def __int__(self):
         """Converts self to an int, truncating if necessary."""
+        return self.__trunc__()
+
+    def __trunc__(self):
+        """Truncates self to an int."""
         if self._is_special:
             if self._isnan():
                 context = getcontext()
@@ -1465,7 +1469,24 @@
             return s*int(self._int)*10**self._exp
         else:
             return s*int(self._int[:self._exp] or '0')
+        
+    def __floor__(self):
+        """Finds the greatest int <= self."""
+        return trunc(self._rescale(0, ROUND_FLOOR))
 
+    def __ceil__(self):
+        """Finds the least int >= self."""
+        return trunc(self._rescale(0, ROUND_CEILING))
+
+    def __round__(self, ndigits:_numbers.Integral=None):
+        """Rounds self to ndigits decimal places, defaulting to 0.
+
+        If ndigits is omitted or None, returns an int, otherwise a
+        Decimal. Rounds half toward even."""
+        if ndigits is None:
+            return trunc(self._rescale(0, ROUND_HALF_EVEN))
+        return self._rescale(-ndigits, ROUND_HALF_EVEN)
+
     def _fix_nan(self, context):
         """Decapitate the payload of a NaN to fit the context"""
         payload = self._int
Index: Lib/numbers.py
===================================================================
--- Lib/numbers.py	(revision 59523)
+++ Lib/numbers.py	(working copy)
@@ -43,7 +43,6 @@
 
 Inexact.register(complex)
 Inexact.register(float)
-# Inexact.register(decimal.Decimal)
 
 
 class Complex(Number):
@@ -274,7 +273,6 @@
         return +self
 
 Real.register(float)
-# Real.register(decimal.Decimal)
 
 
 class Rational(Real, Exact):
Index: Lib/test/test_decimal.py
===================================================================
--- Lib/test/test_decimal.py	(revision 59523)
+++ Lib/test/test_decimal.py	(working copy)
@@ -27,6 +27,7 @@
 
 import unittest
 import glob
+import math
 import os, sys
 import pickle, copy
 from decimal import *
@@ -824,7 +825,45 @@
         self.assertEqual(-Decimal(45), Decimal(-45))           #  -
         self.assertEqual(abs(Decimal(45)), abs(Decimal(-45)))  # abs
 
+    def test_trunc(self):
+        self.assertEqual(int, type(trunc(Decimal("17.5"))))
+        self.assertEqual(17, trunc(Decimal("17")))
+        self.assertEqual(17, trunc(Decimal("17.0001")))
+        self.assertEqual(17, trunc(Decimal("17.999999")))
+        self.assertEqual(-17, trunc(Decimal("-17.999999")))
+        self.assertEqual(10**30, trunc(Decimal("1e30")))
 
+    def test_floor(self):
+        self.assertEqual(int, type(math.floor(Decimal("17.1"))))
+        self.assertEqual(17, math.floor(Decimal("17")))
+        self.assertEqual(17, math.floor(Decimal("17.0001")))
+        self.assertEqual(17, math.floor(Decimal("17.999999")))
+        self.assertEqual(-18, math.floor(Decimal("-17.0001")))
+        self.assertEqual(10**30, math.floor(Decimal("1e30")))
+
+    def test_ceil(self):
+        self.assertEqual(int, type(math.ceil(Decimal("17.1"))))
+        self.assertEqual(17, math.ceil(Decimal("17")))
+        self.assertEqual(18, math.ceil(Decimal("17.0001")))
+        self.assertEqual(18, math.ceil(Decimal("17.999999")))
+        self.assertEqual(-17, math.ceil(Decimal("-17.0001")))
+        self.assertEqual(10**30, math.ceil(Decimal("1e30")))
+
+    def test_round(self):
+        self.assertEqual(int, type(round(Decimal("17.5"))))
+        self.assertEqual(Decimal, type(round(Decimal("17"), 0)))
+
+        self.assertEqual(18, round(Decimal("17.5")))
+        self.assertEqual(16, round(Decimal("16.5")))
+        self.assertEqual(17, round(Decimal("17.4")))
+        self.assertEqual(10**30, round(Decimal("1e30")))
+
+        self.assertEqual(Decimal("17.5"), round(Decimal("17.5"), 1))
+        self.assertEqual(Decimal("1.2e2"), round(Decimal("123.45"), -1))
+        self.assertEqual(Decimal("1.200"), round(Decimal("1.2"), 3))
+        self.assertEqual(Decimal("1" + "0"*30), round(Decimal("1e30"), 0))
+
+
 # The following are two functions used to test threading in the next class
 
 def thfunc1(cls):