Help on dividing a raster into multiple datasets

[Nuno Vilaça]

Dear all,

I am using a raster with a 0.66 x 0.66 m² resolution in which i need
to perform some calculations. As you can imagine, this will take aeons
of time if i do it in the complete raster dataset. I would like to
know how can i divide this raster dataset into e.g. 100 small raster
datasets so i can calculate what i want separately and then append
them. Please specify the tools in a simple way bacause i am new in
this kind of processing!
Thank you for your attention!

Regards.

Nuno