Mom buys a kilogram of rice back at 4.5 yuan per kilogram, and mother gives the salesperson 100 yuan, how much should I get back.
妈妈买回a千克大米，每千克4.5元，妈妈给售货员100元钱，应该找回多少元．
<gadget id="calculator">100 - 4.5</gadget>
<output>95.5</output>

<result>95.5</result>