Uncle Zhang sent 100 vases to a certain company, and the shipping fee was 1.5 yuan each. If there was any damage during the delivery, the shipping fee would not be paid for each damaged one, and 15 yuan would be compensated. After delivery, Uncle Zhang got a shipping fee of 84 yuan. How many vases did he damage?
张叔叔给某个公司送100个花瓶，每个运费1.5元，如果运送途中有损坏，那么每损坏一个不但不给运费，还要赔偿15元．送完货，张叔叔得到运费84元，他损坏了几个花瓶？
<gadget id="calculator">1.5 * 100</gadget>
<output>150</output>

<gadget id="calculator">150 - 84</gadget>
<output>66</output>

<gadget id="calculator">1.5 + 15</gadget>
<output>16.5</output>

<gadget id="calculator">66 / 16.5</gadget>
<output>4</output>

<result>4</result>