Saving Money in Plain English is a Common Craft production that provides a concise explanation of the benefits of saving money in a bank or credit union. While the video doesn’t explain how to calculate compound interest, it does explain the benefit to your savings of compound interest.
Khan Academy has some good videos that introduce and explain how to calculate compound interest. The first two videos in the series are embedded below.
When my school still offered a consumer mathematics course, calculating compound interest was an important concept in the course. These videos could help students understand the benefits of interest and perhaps see why they would want to know how to calculate compound interest.