There is a small pipe 5 meters long, and every 5 decimeters is cut into sections obliquely. After cutting 6 sections, how many decimeters are left?
有一根小管长5米，每5分米斜截成一段，截了6段后，还剩下多少分米？
<gadget id="calculator">5 * 10</gadget>
<output>50</output>

<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<gadget id="calculator">50 - 30</gadget>
<output>20</output>

<result>20</result>