My Grandfather was very successful in business despite a 7th grade education.
A trip to the grocery store with him was both fascinating and embarassing as
he would mentally add every item in his head while the checker was keying the
same (old days -pre-scanner!). He did not round but added to the penny, and if
she did not balance, every item had to be re-rung ...and we're talking about
bags of groceries! I don't think he was ever wrong except when his smartalic
grandkids asked him to divide by 1/2.
VARA EP#67 TR4A