Huafeng Microsoft Corporation produced a batch of software and planned to complete it in 30 days, but actually produced 120 pieces per day, completing the task 5 days earlier than the original plan. How many pieces were originally planned to be produced per day?
华丰微软公司，制作一批软件，计划30天完成，实际每天制作120件，比原计划提前了5天完成任务．原计划每天制作多少件？
<gadget id="calculator">30 - 5</gadget>
<output>25</output>

<gadget id="calculator">25 / 30</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">120 * (5/6)</gadget>
<output>100</output>

<result>100</result>