If the ratio of the number of boys to the number of girls in Class 1 of Grade 5 is 5:4, what is the percentage of boys in the whole class?
五年级一班男生人数与女生人数的比是5：4，则男生人数占全班人数的多少
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>