James buys pistachios for $10 per can.  Each can is 5 ounces.  He eats 30 ounces of pistachios every 5 days.  How much does he spend on pistachios per week?
The pistachios cost 10/5=$
<gadget id="calculator">10/5</gadget>
<output>2</output>
2 per ounce.
He eats 30/5=
<gadget id="calculator">30/5</gadget>
<output>6</output>
6 ounces of pistachios a day.
So he spends 6*2=$
<gadget id="calculator">6*2</gadget>
<output>12</output>
12 per day on pistachios.
So he spends 12*7=$
<gadget id="calculator">12*7</gadget>
<output>84</output>
84 per week.

<result>84</result>