A pile of goods weighs 128 tons. How many tons are left after 20 trucks have been transported by a truck with a load of 4.5 tons?
一堆货物重128吨，用载重4.5吨的卡车运了20车后，还剩下多少吨？
<gadget id="calculator">4.5 * 20</gadget>
<output>90</output>

<gadget id="calculator">128 - 90</gadget>
<output>38</output>

<result>38</result>