is there a way to turn off the rounding?Write your own function. Not rounding is not a good idea. Why do you want to do that?
I'm simulating an aviation radio. 118.225 is a communication frequency. The 3rd decimal place is used for tuning calculation but is not displayed to the pilot. So on my LCD I need it to say COM1 = 118.22 , but when I turn my rotary encoder I'm adding .025 to the frequency. So I need to keep the 3 decimal precision but only display the first 2.