The number of boys in class 51 accounts for 5/9 of the whole class, and how much fewer girls are there than boys
五1班男生人数占全班人数的(5/9)，女生人数比男生人数少多少
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 - (5/9)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(5/9) - (4/9)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/9) / (5/9)</gadget>
<output>1/5 = around 0.2</output>

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