road is 200 meters long, and a tree is planted every 4 meters on both sides of the road, how many trees should be planted in total?
一条马路长200米，在马路两侧每隔4米种一棵树，则一共要种树多少棵．
<gadget id="calculator">200 / 4</gadget>
<output>50</output>

<gadget id="calculator">50 + 1</gadget>
<output>51</output>

<gadget id="calculator">51 * 2</gadget>
<output>102</output>

<result>102</result>