The number of A is 5, and the number of B is 4, then (5-4)/5=20%, which means how much less B is than A
甲数是5，乙数是4，则(5-4)/5=20%，表示乙比甲少多少
<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>