How do I force rotation in 10° steps ?

In a project, the player can use drag and drop to rotate wheels on screen to make combinations.

There's a graduated circle around the wheel with graduation every 10°. Instead of a fluid rotation, I'd like to constrain rotation to steps of 10°, ie wheel's angle should be a multiple of 10. Here's the link to the project to help :

dropbox.com/scl/fi/a4srr9gvq4f4qni8j4dw3/RotatingWheel.c3p

For steps of 10 you can do this when setting the angle:

set angle to round(Self.currentAngle/10)*10

But really with your image this is the correct rounding:

round(Self.currentAngle/(45/9))*45/9