There are 50 black rabbits and 40 white rabbits. How many percent are black rabbits more than white rabbits?
黑兔50只，白兔40只，黑兔比白兔多百分之几？
<gadget id="calculator">50 - 40</gadget>
<output>10</output>

<gadget id="calculator">10 / 40</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>