The diameter of the small circle is 3 cm, the diameter of the large circle is 5 cm, and the circumference of the small circle is equal to the circumference of the large circle.
小圆的直径是3cm，大圆的直径是5cm，小圆的周长是大圆周长的多少．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>