Yingcai Primary School has 80 students in the sixth grade, 100 students in the fifth grade, and 70 students in the fourth grade. The students in the three grades account for (5/8) of the total number of students in the school. Find the total number of students in the school. (solution by equation)
英才小学六年级有学生80人，五年级有学生100人，四年级有学生70人，三个年级的学生数共占学校学生总数的(5/8)，求全校学生的总数．(用方程解)
<gadget id="calculator">100 + 80 + 70</gadget>
<output>250</output>

<gadget id="calculator">5 / 8</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">250 / (5/8)</gadget>
<output>400</output>

<result>400</result>