The law of a series of numbers 1, 4, 7, 10...100 is: the first number is 1, and each subsequent number is equal to the previous number plus 3, until 100. When multiplying all these numbers together, how many consecutive zeros are there at the end of the resulting product?
一串数1，4，7，10…100的规律是：第一个数为1，以后的每一个数都等于它前面的一个数加3，直到100止．将所有这些数相乘，所得积的尾部有多少个连续的零．
<gadget id="calculator">100 - 10</gadget>
<output>90</output>

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">90 / 15</gadget>
<output>6</output>

<gadget id="calculator">6 + 1 + 2</gadget>
<output>9</output>

<result>9</result>