Press different numbers for different blocks. Press see inside to use the blocks. Press 1: Previous Costume. So you know I'm not lying, press the right arrow for next costume. Press 2: Round to nearest 5. Press 3: Previous Backdrop. So you know I'm not lying press the left arrow for next backdrop. Press 4: The sprite will say the time. Press 5: Round to nearest 10.
I figured out a better way to do rounding when I saw @Gold_Creator's grid placing system