first you start with 0 then you know that is yours nothing so you can cancel zero and then you can take the eight can round up so you take the 8 and put it one more to do so it's $4 so in total will be $4 that's the answer
To round to the nearest dollar u will have to look at the numbers after the decimal specifically the tenth so the 8. if its more than 5 then or 5 move the dollar up if its less than 4 or 4 then leave the dollar the same. at the end u will get $4.00.
