Positive odds 0.90
If the odds are positive
Each bet ticket is worth 1000 with odds of 0.90; will win an amount of 900 ; If the bet loses, the player will lose 1000.

Negative odds -0.90
If the odds are negative values
Each bet ticket is worth 1000 with odds -0.90; will win 1000 ; If the bet loses, the player will lose the amount = -0.9*1000 = 900