Find the smaller angle between the hands of the clock in the picture.

The clock shows 9:30. Hour hand: $30\times 9+\frac{30}{2}=285^{\circ }$; minute hand: $6\times 30=180^{\circ }$. The gap is $105^{\circ }$. (90° forgets that the hour hand has moved halfway towards 10; 255° is the reflex angle.)