A stationery factory makes pencil cases. It used to cost 3.6 yuan of materials to make a pencil case. After improving the production method, it now only needs 3.2 yuan of materials. It used to make 120 pencil cases. How many more can it make now?
某文具厂做笔袋，原来做一个笔袋需要3.6元的材料，改进制作方法后，现在每只需要用3.2元的材料，原来做120个笔袋的材料，现在可以多做多少个？
<gadget id="calculator">120 / 3.2</gadget>
<output>37.5</output>

<gadget id="calculator">3.6 * 37.5</gadget>
<output>135</output>

<gadget id="calculator">135 - 120</gadget>
<output>15</output>

<result>15</result>