Odds of winning TOTO (Singapore)

Group 1 prize: 6 numbers = 1 in 8,145,060

Group 2 prize: 5 numbers plus the additional number = 1 in 1,357,510

Group 3 prize: 5 numbers = 1 in 35,724

Group 4 prize: 4 numbers plus the additional number = 1 in 14,290

Group 5 prize: 4 numbers = 1 in 772

Group 6 prize: 3 numbers plus the additional number = 1 in 579

Any prize = 1 in 321

Then why is my probably always 0...sigh