After converting (15/60) into the simplest fraction, what is its fractional unit
把(15/60)化成最简分数后，它的分数单位是多少
<gadget id="calculator">60 / 15</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>