Use a piece of cloth 4 meters long to make 8 vests of the same size, how many decimeters of cloth are used for each vest?
用一段长4米的布做8件同样大的背心，每件背心要用多少分米的布？
<gadget id="calculator">4 * 10</gadget>
<output>40</output>

<gadget id="calculator">40 / 8</gadget>
<output>5</output>

<result>5</result>