In the fifth grade mathematics final exam, there are 72 students with excellent grades, just accounting for 50% of the whole grade. How many students are there in the whole grade?
五年级数学期末考试，成绩优良的有72人，刚好占全年级的50%，全年级有学生多少人？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">72 / (1/2)</gadget>
<output>144</output>

<result>144</result>