Hey just need some help with absolute and relative errors

q) find the absolute and relative error when a computer stores 2/3 (two thirds)

q2)then calculate the absolute and relative error when a computer adds

2/3 + 2/3 + 2/3 (two thirds + two thirds + two thirds)

Some direction to a tutorial or some help would be nice(Headbang)(Headbang)(Headbang)(Headbang)(Headb ang)(Headbang)