There are 6 periods in the day for a normal student but John has to take 2 extra classes.  Each class is 40 minutes long.  He goes to class for 5 days a week.  He then spends 1/16 of his weekly minutes each on Saturday and Sunday as extra learning time.  How many hours a week does he spend learning?
He takes 6+2=
<gadget id="calculator">6+2</gadget>
<output>8</output>
8 classes a day.
That means he spends 40*8=
<gadget id="calculator">40*8</gadget>
<output>320</output>
320 minutes per day in class.
So he spends 320*5=
<gadget id="calculator">320*5</gadget>
<output>1_600</output>
1600 minutes a week.
That means he spends 1600/16=
<gadget id="calculator">1600/16</gadget>
<output>100</output>
100 minutes each on Saturday and Sunday.
So he spends 1600+100+100=
<gadget id="calculator">1600+100+100</gadget>
<output>1_800</output>
1800 minutes per week.
So he spends 1800/60=
<gadget id="calculator">1800/60</gadget>
<output>30</output>
30 hours per week.

<result>30</result>