Sunita has 75 pens and she ties them into bundles of 8. How many pens does she have left over?

We can work the remainder by using division, and one of the most common methods to use is long division. (Here I would present the method on a whiteboard)

As we can see, the closest multiple of 8 to 75 is 72, which leaves a remainder of 3.

Therefore, Sunita has 3 pens left over.