Use one truck to transport 42,000 kilograms of cement. It has been transported 4 times, and each time it transports 5,000 kilograms. How many kilograms must be transported to finish?
用一辆卡车运42000千克水泥，已经运了4次，每次运5000千克，还要运多少千克才能运完？
<gadget id="calculator">5_000 * 4</gadget>
<output>20_000</output>

<gadget id="calculator">42_000 - 20_000</gadget>
<output>22_000</output>

<result>22_000</result>