There are 45 students in Class 1, 80% of which are boys. How many girls are there? (Solved using equations and conversion methods)
六1班有学生45人，男生是女生的80%．女生有多少人？(用方程和转化方法解)
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 + (4/5)</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">45 / (9/5)</gadget>
<output>25</output>

<result>25</result>