John buys 5 notebooks that have 40 pages each.  He uses 4 pages per day.  How many days do the notebooks last?
He got 5*40=
<gadget id="calculator">5*40</gadget>
<output>200</output>
200 pages.
So they will last 200/4=
<gadget id="calculator">200/4</gadget>
<output>50</output>
50 days.

<result>50</result>