Rounding ALWAYS takes place after the full operation is performed.

-(-26.5)^2 - (-9.85)^3 = 253.421625

to nearest whole number: 253

to 1 decimal place: 253.4

to 2 decimal places: 253.42

to 3 decimal places: 253.422

to 4 decimal places: 253.4216

to 5 decimal places: 253.42163

to 6 decimal places: 253.421625