DOCS-563 minor edits

Author: kay-kim

source/core/object-id.txt

@@ -39,7 +39,7 @@ helper attribute and methods:
 
 - ``str``
 
-   The hexadecimal string value of the ``ObjectID()`` object.
+   The hexadecimal string value of the ``ObjectId()`` object.
 
 - :method:`getTimestamp() <ObjectId.getTimestamp()>`
 
@@ -51,7 +51,7 @@ helper attribute and methods:
    returned string literal has the format "``ObjectId(...)``".
 
    .. versionchanged:: 2.2
-      In previous versions :method:`ObjectId.toString()>` returns the
+      In previous versions :method:`ObjectId.toString()` returns the
       value of the ObjectId as a hexadecimal string.
 
 - :method:`valueOf() <ObjectId.valueOf()>`
@@ -60,10 +60,10 @@ helper attribute and methods:
    The returned string is the ``str`` attribute.
 
    .. versionchanged:: 2.2
-      In previous versions :method:`ObjectId.valueOf()>` returns the
-      value of the ObjectId as a hexadecimal string.
+      In previous versions :method:`ObjectId.valueOf()` returns the
+      ``ObjectId()`` object.
 
-Consider the example uses of the ``ObjectID()`` class in the
+Consider the example uses of the ``ObjectId()`` class in the
 :program:`mongo` shell:
 
 - To generate a new ObjectId, use the ``ObjectId()`` constructor with
@@ -92,7 +92,8 @@ Consider the example uses of the ``ObjectID()`` class in the
 
      ObjectId("507f191e810c19729de860ea")
 
-- To return the timestamp of an ``ObjectId()`` object:
+- To return the timestamp of an ``ObjectId()`` object, use the
+  :method:`getTimestamp() <ObjectId.getTimestamp()>` method as follows:
 
   .. code-block:: javascript
 

source/reference/method/ObjectId.toString.txt

@@ -12,10 +12,10 @@ ObjectId.toString()
 
    .. versionchanged:: 2.2
       In previous versions :method:`ObjectId.toString()` returns the
-      value of the ObjectId as a hexadecmial string.
+      value of the ObjectId as a hexadecimal string.
 
    In the following example, call the :method:`toString()
-   <ObjectId.toString()>` method on an ObjectID
+   <ObjectId.toString()>` method on an ObjectId
    (e.g. ``ObjectId("507c7f79bcf86cd7994f6c0e")``), as follows:
 
    .. code-block:: javascript

source/reference/method/ObjectId.valueOf.txt

@@ -15,7 +15,7 @@ ObjectId.valueOf()
       the ``ObjectId()`` object.
 
    In the following example, call the :method:`valueOf()
-   <ObjectId.valueOf()>` method on an ObjectID
+   <ObjectId.valueOf()>` method on an ObjectId
    (e.g. ``ObjectId("507c7f79bcf86cd7994f6c0e")``), as follows:
 
    .. code-block:: javascript