Two gears meshing with each other, if the large and small gear ratio is 5:4, the wheel speed ratio is 1:1, the large gear makes 100 revolutions, how many revolutions does the small gear need to make.
两个互相咬合的齿轮，如果大小齿数比为5：4，轮速比是1：1，大齿轮转100圈，小齿轮要转多少圈．
<gadget id="calculator">100 * 5</gadget>
<output>500</output>

<gadget id="calculator">500 / 4</gadget>
<output>125</output>

<result>125</result>