The number of students in the fourth, fifth and sixth grades of a certain school is equal, and there are 445 students with normal eyesight in the three grades, accounting for (5/6), (8/9) and (3/4) of the students in this grade respectively. How many students with abnormal vision in the three grades?
某校四、五、六年级的学生人数相等，三个年级中视力正常的学生共445人，分别占本年级学生人数的(5/6)，(8/9)和(3/4)．三个年级中视力不正常的学生共有多少人？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">8 / 9</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(5/6) + (8/9) + (3/4)</gadget>
<output>89/36 = around 2.472222</output>

<gadget id="calculator">445 / (89/36)</gadget>
<output>180</output>

<gadget id="calculator">180 * 3</gadget>
<output>540</output>

<gadget id="calculator">540 - 445</gadget>
<output>95</output>

<result>95</result>