The students planted flowers. The third grade planted 35 trees, and the second grade planted 28. How many percent were the second grade plants less than the third grade?
同学们种花，三年级种了35棵，二年级种了28棵，二年级比三年级少种了百分之几？
<gadget id="calculator">35 - 28</gadget>
<output>7</output>

<gadget id="calculator">7 / 35</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>