nsdecimalnumber - Examples of doing decimal math in iPhone -

i'm pulling decimal values sql table text field convert nsdecimalnumber (this because didnt know read/write decimal values sqllite).

anyway, i've hit wall im trying simple math routines on these decimal variables. such as, sum = balance * interest_rate. idea im working money calculations.

do know of samples/tutorials teaches how these operations using either nsdecimal, nsdecimalnumber, or both?

thanks.

to init:

nsstring *number = @"123.4"; nsdecimalnumber *mydecimal = [[nsdecimalnumber alloc] initwithstring: number]; 

to want do:

nsdecimalnumber *sum = [[nsdecimalnumber alloc] initwithdecimal:[balance decimalnumberbymultiplyingby: interest_rate]; 

how?

well make nsdecimalnumber , alloc , initwithdecimal. decimal? balance multiplied (decimalnumberbymultiplyingby) interest_rate.