Cindy was 5 years old.  Her sister Jan was 2 years older than Cindy.  Their oldest sister Marcia was twice as old as Jan.  Greg was two years older than Marcia.  How old was Greg?
Jan was 2 years older than Cindy who was 5 so 2+5 = 
<gadget id="calculator">2+5</gadget>
<output>7</output>
7 years old.
Marica was twice as old as Jan so 2*7 = 
<gadget id="calculator">2*7</gadget>
<output>14</output>
14 years old.
Greg was 2 years older than Marcia who was 14 so 2+14 = 
<gadget id="calculator">2+14</gadget>
<output>16</output>
16 years old.

<result>16</result>