How to do a 20% Discount on Ticklet Total up to the value of $50

I’m trying to implement a discount on Ticket Total up to a certain value. After ready a few discounting tutorial on the forum, I decide to use Calculation Type to do this.

What I did was set up a 20% rate from Ticket Amount, and set $10 as Max Amount, but it’s not working as expected.

Basically what I’m trying to do is,

  • when ticket total is $50 or less, then simply apply 20% discount on ticket total
  • when ticket total is greater than $50, than 20% is applied to the first $50 (50x0.2=10 therefore Max Amount is $10), and amount over $50 is not discounted.

so (a) Ticket total of $30, apply 20% discount, equals $24 ( $6 discount)
(b) Ticket total of $50, apply 20% discount, equals $40 ( $10 discount)
© Ticket total of $80, apply 20% discount, equals $70 ( discount capped at $10)

Any suggestions on how I can achieve this??

Thanks in advance.