From one end of the playground, a wooden stake is nailed every 4m, a total of 25 wooden stakes are nailed, and now it is changed to a wooden stake every 6m. How many stakes are there that cannot be pulled out?
从运动场的一端，每隔4m钉一根木桩，一共钉了25根木桩，现在改成每隔6m钉一根木桩．可以不拔出来的木桩有多少根？
<gadget id="calculator">25 - 1</gadget>
<output>24</output>

<gadget id="calculator">4 * 24</gadget>
<output>96</output>

<gadget id="calculator">96 / 12</gadget>
<output>8</output>

<gadget id="calculator">8 + 1</gadget>
<output>9</output>

<result>9</result>