Megan is an actress. She was the lead actress in 80% of her work. In total, Megan participated in 100 plays. How many times Megan was not the lead actress?
Megan was the lead actress in 100 * 80% = 
<gadget id="calculator">100*80*.01</gadget>
<output>80</output>
80 plays.
So Megan was not the lead actress in 100 - 80 = 
<gadget id="calculator">100-80</gadget>
<output>20</output>
20 plays.

<result>20</result>