How to turn 3/9 in to a decimal ? no calculator

Can someone pls ! pls answer all. no explanation needed..

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

Which equation represents the model shown? a)1/3 divide 1/6 = 2 b)2/3 divide 1/6 = 2/18 c)1/3 divide 1/6 = 1/18 d)2/3 divide 1/6 =4