Susie's pet lizard Moe takes 10 seconds to eat 40 pieces of cuttlebone each day. How long would it take Moe to eat 800 pieces?
If it takes Moe 10 seconds to eat 40 cuttlebones, then in one second she eats 40 cuttlebones / 10 seconds = 
<gadget id="calculator">40/10</gadget>
<output>4</output>
4 cuttlebones/second.
Since the cat eats 4 pieces of cuttlebone in 1 second, 800 pieces will be 800 cuttlebones / 4 cuttlebones/second = 
<gadget id="calculator">800/4</gadget>
<output>200</output>
200 seconds.

<result>200</result>