The Experimental Primary School carried out the "Tree Planting·Environmental Protection" activity, and 200 saplings were brought in. The teacher planted 10%, and the rest was distributed to Class A and Class B at a ratio of 5:7. How many fewer trees will Class A plant than Class B?
实验小学开展"植树•环保"活动，运来了200棵树苗，老师栽种了10%，余下的按5：7分配给甲、乙两个班级，这样甲班比乙班少植多少棵树？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">(9/10) / 12</gadget>
<output>3/40 = around 0.075</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">200 * (3/40) * 2</gadget>
<output>30</output>

<result>30</result>