thermos is 38.5 yuan, a teacup is 10.5 yuan, an iron pot is 22.8 yuan, and an electric kettle is 15 yuan. Xiao Ming's mother bought a thermos and two iron pots in the supermarket. She paid 100 yuan when paying the bill. How much should I get back?
一只保温瓶38.5元，一只茶杯10.5元，一口铁锅22.8元，一只电水壶15元．小明的妈妈在超市买了一只保温瓶和两口铁锅，交款时她付了100元，应找回多少元？
<gadget id="calculator">2 * 22.8</gadget>
<output>45.6</output>

<gadget id="calculator">38.5 + 45.6</gadget>
<output>84.1</output>

<gadget id="calculator">100 - 84.1</gadget>
<output>15.9</output>

<result>15.9</result>