Nadia is learning to play the piano. She normally makes 3 mistakes per 40 notes and can play about 60 notes a minute.   If she plays for 8 minutes how many mistakes will she make on average?
She plays 480 notes because 8 x 60 = 
<gadget id="calculator">8*60</gadget>
<output>480</output>
480.
This is 12 blocks of 40 notes because 480/40=
<gadget id="calculator">480/40</gadget>
<output>12</output>
12.
She makes 36 mistakes because 12 x 3 = 
<gadget id="calculator">12*3</gadget>
<output>36</output>
36.

<result>36</result>