On a tractor, the diameter of the rear wheel is twice that of the front wheel, and the rear wheel has 8 turns, how many turns does the front wheel turn?
一台拖拉机，后轮直径是前轮的2倍，后轮8圈，前轮转动多少圈
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<result>16</result>