## Explanation

For this example, we want to calculate cumulative principal payments over the full term of a 5-year loan of $5,000 with an interest rate of 4.5%. To do this, we set up CUMPRINC like this:

**rate** - The interest rate per period. We divide the value in C6 by 12 since 4.5% represents annual interest:

```
=C6/12
```

**nper** - the total number of payment periods for the loan, 60, from cell C8.

**pv** - The present value, or total value of all payments now, 5000, from cell C5.

**start_period** - the first period of interest, 1 in this case, since we are calculating principal across the entire loan term.

**end_period** - the last period of interest, 60 in this case for the full loan term.

With these inputs, the CUMPRINC function returns 5,000, which matches the original loan value as expected.