This is a way to introduce students to compounding continuously.
Compound Interest, Clip 2, 4:48
The teacher is taking this opportunity to discuss a monthly growth factor and develop the compound interest formula. This will help the students make sense of the formula and why they divide the interest rate by the number of compounding periods.
She also points out the monthly growth rate and what percent they would make each month, thus differentiating it with the annual growth rate and the nominal growth rate.
Then she extends the period to 7 years which actually brings out some misconceptions by the students (both about teh formula and how it should be put int the calculator).