There is a pile of bricks in the school, totaling 300 pieces. To build a stove and a water well for the students, 200 pieces are used to build the stove, and the rest are used to build the water well. What percentage of the pile of bricks are the bricks used to build the water well?
学校有一堆砖，共有300块，要给学生砌一盘灶和一个水井，砌灶用了200块，其余的用来砌水井，砌水井的砖占这堆砖的几分之几？
<gadget id="calculator">300 - 200</gadget>
<output>100</output>

<gadget id="calculator">100 / 300</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>