You want to know what the hot dog business is theoretically worth. You believe the hotdog stand is a relatively low-risk venture and assume the cash flows should be discounted at a rate of 10% per year.
Once you have the discount rate you like (10%) and the free-cash-flow projections (listed above), the next step is to start doing the math.
Discounting the cash flows
To calculate the present value of any cash flow, you need the following formula: Present value = expected cash flow ÷ (1 + discount rate)^number of periods
Year one
For year one, the math would look like this:
Present value = $50 ÷ (1 + .10)^1
Present value = $50 ÷ (1.10)^1
Present value = $50 ÷ 1.10
Present value = $45.45
In completing the steps, you learn that the present value of $50 is $45.45 at a 10% discount rate. Hence, the year one cash flow of $50 has a present value of $45.45.