how can I caculate with numbers bigger than a word using 16F88 ?

[rmteo]

I'm with you, Charles, but is there a PIC18 that is nearly the same price as a PIC16F88? I'm doing a low cost consumer product right now where 40 cents makes a big difference. Until that time, that evil PIC16F architecture lives on.

According to here PIC16F88 the lowest cost device is $2.20 - if you go here PIC18 Product Family and do a sort on ascending price, you will find about 45 PIC18's that cost less than a PIC16F88. That said, I use several competitive 32-bit devices that are about half that price.