To let Ruth know how long her fish will live, her father tells her that well-cared fish can live 2 years longer than dogs live. On average, dogs live 4 times as long as hamsters live. And hamsters live an average of 2.5 years. How long can a fish live?
Knowing that dogs live 4 times the age of hamsters, dogs live 4 * 2.5 = 
<gadget id="calculator">4*2.5</gadget>
<output>10</output>
10 years.
If Ruth takes care of the fish, it can live 10 + 2 = 
<gadget id="calculator">10+2</gadget>
<output>12</output>
12 years.

<result>12</result>