Twice Angie's age, plus 4, is 20. How old is Angie?
Twice Angie's age is 20-4=
<gadget id="calculator">20-4</gadget>
<output>16</output>
16.
Angie is 16/2=
<gadget id="calculator">16/2</gadget>
<output>8</output>
8.

<result>8</result>