In the math test of Class 61 of Guangming Primary School, the average grade of the whole class was 90 points, of which the average score of boys was 88 points, and the average score of girls was 93 points. It is known that there are 9 fewer girls than boys. How many students are there in this class?
光明小学六一班一次数学考试中，全班平均平绩是90分，其中男生平均分88分，女生平均分93分，已知女生比男生人数少9人，这个班共有学生多少人．
<gadget id="calculator">9 * 93</gadget>
<output>837</output>

<gadget id="calculator">9 * 90</gadget>
<output>810</output>

<gadget id="calculator">837 - 810</gadget>
<output>27</output>

<gadget id="calculator">93 - 90 - 90</gadget>
<output>-87</output>

<gadget id="calculator">88 + (-87)</gadget>
<output>1</output>

<gadget id="calculator">27 / 1</gadget>
<output>27</output>

<gadget id="calculator">27 - 9</gadget>
<output>18</output>

<gadget id="calculator">27 + 18</gadget>
<output>45</output>

<result>45</result>