Each refill is 0.65 yuan. The school bought two for each of the 48 teachers and paid 100 yuan. How much should I get back?
每支笔芯0.65元，学校为48位教师每人买两支，付出100元，应找回多少元？
<gadget id="calculator">0.65 * 2 * 48</gadget>
<output>62.4</output>

<gadget id="calculator">100 - 62.4</gadget>
<output>37.6</output>

<result>37.6</result>