A piece of iron wire is 20 decimeters long. Now fold it into a rectangle whose length is 6 decimeters. What is the width of this rectangle?
一根铁丝长20分米，现在把它折成一个长是6分米的长方形，这个长方形的宽是多少分米？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<result>4</result>