Negotiating for a higher salary can be a stressful ordeal. You obviously want to be paid fairly for your work, but you do not want to risk upsetting your employer by throwing out numbers that might be too large. According to a study done by researchers at the Columbia Business School, giving precise numbers is more likely to result in a higher final statement.
For example, instead of asking for $70,000, consider $69,450. Even if your initial demand is less, you are still likely to come out with more than you would with a round number. When employees give out round numbers, employers usually assume that they are simply throwing out a rough estimate. Giving a precise number shows your employer that you are aware of your worth as an employee as well as the desire and ability of the company to pay more to maintain you.