There are 45 students in Class 2 of the fifth year. In the school sports meeting, 18 students participated in the running competition, accounting for the number of the whole class.
五年2班有学生45人，在学校运动会上，有18人参加跑步比赛，占全班人数的多少．
<gadget id="calculator">18 / 45</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>