How does an 8bit MCU make use of data-types over 8bits? how does an 8bit MCU handle 16bit output?
How does an 8bit MCU store values higher than 8bits?
I am using an attiny, on an adafruit trinket. and other 8bit MCUs.
http://www.atmel.com/devices/attiny85.aspx
I was doing some things with uint32_t datatypes, when it hit me, that it would seem like uint32_t would be an incompatible datatype. Even 2Byte data type like int seems peculiar. "int stores a 16-bit (2-byte) value"
considering the MCU is 8bit. 

I saw this link, that sounded like it would have more info, but its pages are incomplete. http://playground.arduino.cc/Code/DatatypePractices

So how does that work?
How does an 8bit MCU make use of data-types over 8bits?
The basic answer is that the processor does math in 8-bit chunks, so it takes more instructions than it would on a 32-bit processor.

A good answer is found in EE.SE