There are 45 students in Class 1, of which boys account for (4/9), and the number of boys who are short-sighted (1/5), how many boys are short-sighted?
六1班有学生45人，其中男生占(4/9)，男生中近视的人数占(1/5)，近视的男生有多少人．
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">45 * (4/9) * (1/5)</gadget>
<output>4</output>

<result>4</result>