A 21-meter-long rope is folded in half and then folded in half again. What is the length of each piece?
一根21米长的绳子，对折再对折后，每段长是多少米
<gadget id="calculator">21 / 4</gadget>
<output>21/4 = around 5.25</output>

<result>21/4 = around 5.25</result>