A store entrusts a moving station to deliver 150 vases. The two parties agreed on a shipping fee of 1 yuan for each piece, but if any damage occurs, the shipping fee will not be paid for each broken piece, and a compensation of 2 yuan will be required. Question: How many vases were broken during the transportation?
某商店委托搬运站运送150只花瓶．双方商定每只运费1元，但如果发生损坏，那么每打破一只不仅不给运费，而且还得赔偿2元，结果搬运站共得到运费135元．问：搬运过程中共打破几只花瓶？
<gadget id="calculator">1 * 150</gadget>
<output>150</output>

<gadget id="calculator">150 - 135</gadget>
<output>15</output>

<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<result>5</result>