The fifth grade accounts for 1/4 of the whole school, the fourth grade is more than the fifth grade (1/4), what percentage of the fourth grade accounts for the whole school? What percentage of the total number of students in the fourth and fifth grades?
五年级的人数占全校的(1/4)，四年级的人数比五年级多(1/4)，四年级占全校人数的几分之几？四五年级共占全校人数的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(1/4) * (5/4)</gadget>
<output>5/16 = around 0.3125</output>

<gadget id="calculator">(1/4) + (5/16)</gadget>
<output>9/16 = around 0.5625</output>

<gadget id="calculator">(9/16) / 1</gadget>
<output>9/16 = around 0.5625</output>

<result>9/16 = around 0.5625</result>