A manuscript paper has 4 pages, 180 characters per page, and only 8 lines can be written on a blackboard. How many words can be written on average per line to finish the manuscript?
一份稿纸共4页，每页180个字，一个黑板只能写8行，平均每行写多少个字才能写完这份稿件？
<gadget id="calculator">4 / 8</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">180 * (1/2)</gadget>
<output>90</output>

<result>90</result>