The price per kilogram of a kind of tea is 48.5 yuan. My mother bought 0.5 kilograms and paid 100 yuan. How much should I get back?
一种茶叶每千克的售价是48.5元，妈妈买0.5千克，付了100元，应找回多少元．
<gadget id="calculator">48.5 * 0.5</gadget>
<output>24.25</output>

<gadget id="calculator">100 - 24.25</gadget>
<output>75.75</output>

<result>75.75</result>