Terry eats 2 yogurts a day.  They are currently on sale at 4 yogurts for $5.00.  How much does he spend on yogurt over 30 days?
He eats 2 yogurts a day so over 30 days he will need 2*30 = 
<gadget id="calculator">2*30</gadget>
<output>60</output>
60 yogurts.
The yogurt is sold as 4 units for $5.00 and he needs 60 yogurts so that's 60/4 = 
<gadget id="calculator">60/4</gadget>
<output>15</output>
15 4-packs.
Each 4-pack is $5.00 and he needs 15 4-packs so he will spend $5*15 = $
<gadget id="calculator">5*15</gadget>
<output>75</output>
75.00 on yogurt.

<result>75</result>