A truck with a load of 3.5 tons has to transport 50 tons of goods. After several times of transportation, there are still 29 tons left to be transported. How many times has the truck been shipped?
一辆载重3.5吨的货车，要运50吨货物，运了几次后，还剩下29吨没运．货车运了几次？
<gadget id="calculator">50 - 29</gadget>
<output>21</output>

<gadget id="calculator">21 / 3.5</gadget>
<output>6</output>

<result>6</result>