A freight train has 9 carriages, and each carriage carries 50 tons of coal. If it is carried 7 times like this, how many tons of coal can be transported in total?
一列货运火车有9节车厢，每节车厢载50吨煤，如果照这样运7次，一共可以运多少吨煤？
<gadget id="calculator">50 * 9 * 7</gadget>
<output>3_150</output>

<result>3_150</result>