#1 -- there is no nearest fraction.

Nearest half (1/2), multiply by 2 and round result to near whole number

Nearest fourth (1/4), multiply by 4 and round result to near whole number

Nearest tenth (1/10), multiply by 10 and round result to near whole number

Nearest 16th, multiply by 16 and round result to near whole number

Nearest 64th, multiply by 64 and round result to near whole number

There's a theme here.