Mom went to the flower shop and bought 1.8 meters of cloth at 38.4 yuan per meter. Mom gave the salesperson 100 yuan. How much should I get back?
妈妈去花布店买了1.8米布，每米38.4元，妈妈给售货员100元，应找回多少元？
<gadget id="calculator">1.8 * 38.4</gadget>
<output>69.12</output>

<gadget id="calculator">100 - 69.12</gadget>
<output>30.88</output>

<result>30.88</result>