Help with working memory!!!!

[Basak97]

Hi I need help with understanding Alan Baddeley and Graham Hitch's model of working memory
I just can't seem to understand it and the relation between the sub components
I would appreciate it if someone explained it thoroughly with an appropriate example to help me make some sort if a link
Thanks

[DoctorWho]

Two Storage Components:
Phonological Loop - Auditory working memory storage.

Visuo-spatial Sketchpad - Visual working memory storage.

Two Functional Components:
The Central Executive - Integrates the other components of working memory. Decides which information from LTM is needed to help process the information in STM and decide which information should be transferred to LTM.

Episodic Buffer - Helps retrieve information from LTM and encode information which the central executive has selected to be placed in LTM.

EXAMPLE:
To work out "7 x 43="
Visuo-spatial sketchpad enables us to picture the problem.
Phonological Loop allows us to sound the problem out in our heads.
Central Executive enables us to realise that we are going to need to retrieve our 7x tables from LTM.
Episodic Buffer retrieves the 7x tables from LTM.
Central Executive works out 7x3=21 and 7x40=280.
Phonological Loop holds the sounds of 21 and 280 in our heads.
Central Executive reaches answer of 301.
Phonological Loop holds this number's sound, enabling us to say it when ready.
Central Executive decides if we commit this to LTM.
Episodic Buffer encodes information to LTM (if need be).