If 500 trees are planted in the school campus, if the survival rate is required to be 99%, how many trees can die at most?
学校校区栽树500棵，如要求成活率是99%，最多能死多少棵．
<gadget id="calculator">1 / 100</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">500 * (1/100)</gadget>
<output>5</output>

<result>5</result>