There is a set of gears meshing with each other. The large gear has 140 teeth, and the small gear has 1/5 of the teeth of the large gear. How many teeth does the small gear have?
有一组互相咬合的齿轮，大齿轮有140个齿，小齿轮的齿数是大齿轮的(1/5)，小齿轮有多少个齿？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">140 * (1/5)</gadget>
<output>28</output>

<result>28</result>