這是不好理解，如果假設第10年淨收入是18.6萬，簡單地按照15%折現到現在，應該是18.6/(1+0.15)^10=4.5976.而實際上是每一個時間點都要折現到現在。
並且折現方法有幾種，我選擇合理的連續複利折現方式。具體見下表，為10％的折現結果：
| Cum. | 10% | ||||||
| Total Net | Severance | Operations | Capital | Cash Flow | Cash Flow | Cum. Disc. | |
| MO-YR | Revenue | Taxes | Cashflow, M$ | Costs,M$ | BTAX, M$ | BTAX, M$ | BTAX, M$ |
| 12-Jan | 12 | 2.4 | 9.6 | 110 | -100.4 | -100.4 | -95.764 |
| 13-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -90.8 | -87.44 |
| 14-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -81.2 | -79.872 |
| 15-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -71.6 | -72.993 |
| 16-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -62 | -66.738 |
| 17-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -52.4 | -61.053 |
| 18-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -42.8 | -55.884 |
| 19-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -33.2 | -51.185 |
| 20-Jan | 12 | 2.4 | 9.6 | 0 | 9.6 | -23.6 | -46.914 |
| 21-Jan | 12 | 2.4 | 9.6 | -200 | 209.6 | 186 | 37.873 |
| Subtotal | 120 | 24 | 96 | -90 | 186 | 186 | 37.873 |
| Present Worth Profile | ||||
| Disc | PW of Net | Disc | PW of Net | |
| Rate | BTAX, M$ | Rate | BTAX, M$ | |
| 0 | 186.000 | 30 | -46.228 | |
| 2 | 143.879 | 35 | -53.030 | |
| 5 | 94.434 | 40 | -57.641 | |
| 8 | 57.383 | 45 | -60.773 | |
| 10 | 37.873 | 50 | -62.888 | |
| 12 | 21.625 | 60 | -65.204 | |
| 15 | 2.109 | 70 | -66.049 | |
| 18 | -12.903 | 80 | -66.125 | |
| 20 | -20.972 | 90 | -65.790 | |
| 25 | -36.130 | 100 | -65.230 |
