Decreasing how many decimal places to show actually changing the value of the number. Want to turn off.

I'm working in a spreadsheet someone sent to me. If I type a number like 5.71254 into a cell but then reduce the amount of decimal places I'd like shown to 2, then Excel will actually change the value of the cell 5.71. If I look up the the formula bar the value will be 5.71. I have lost the .00254 by only reducing decimal places shown.

The cell is simply a value there are no formulas involved. I've never seen this happen. I'm sure it is an option you can turn on/off somewhere, but I can't find it (quickly). Anybody know how to turn this off?