I recently had a bet with a group of office workers on who could get the best Calculator for the least amount of money. I won. I knew Overstock would have just what I wanted at the best price . This is a great little machine and I am so glad that once again I went to Overstock.com and looked first. Machine does just what I want adds and subtracts all the math duties you could want. I am not in to advanced math so I cant speak to that but this is one good purchase. Yea