True. The simple interest formula calculates the interest earned on the principal amount over a certain period, but to find the total account value at the end of that period, you need to add the interest amount to the principal. The total account value can be expressed as:
Total Account Value = Principal + Interest
Where Interest is calculated using the simple interest formula:
Interest = Principal × Rate × Time
Thus, adding the interest to the principal gives you the total value in the account.