You can control your mouse pointer with your numeric keys. This steps becomes very usefull when suddenly your mouse dosnt’ works properly or you dont’ have mouse. your keyboard performs all the functions of your normal mouse.
follow the steps to activate your keyboard mouse.

Ease of Access

Change How your Mouse works

Turn on Mouse keys
Another way to activate Mouse keys
press Alt+Shift+NumLock keys at once and you will get a small Mouse Keys dialog box.
Click on Yes

At any instance of time you can quickly enable or disable Mouse keys by pressing NumLock button.
Move your cursor into different directions using 1,2,3,4,6,7,8 and 9 keys.
Key 5 will work as your left mouse click.
To double click any object use + Sign key.
Nice trick….thanks Rahul