A square with a side length of 4 decimeters is surrounded by a piece of iron wire. If it is changed into a rectangle with a length of 5 decimeters, what is the width of this rectangle?
用一条铁丝围成一个边长是4分米的正方形，如果把它改为围成一个长为5分米的长方形，那么这个长方形宽是多少分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">8 - 5</gadget>
<output>3</output>

<result>3</result>