I would like to generate numbers by an actor taking damage percent (also will be displayed )when hit and the make the number add by the number of damage taken the max number would be 999 any suggestions?
You could try creating a RandomFloatInRange module called with an onHit event. You have to set up a minimum value of 0 and a maximum of 999. This will make you generate random numbers. But I didn’t really understand what you want to achieve, so if you could write something more clear I would help you 
I wanna acheuve something like super smash bros. When you get hit a damage percent comes up the higher the percent the further you get knocked off screen
So, you want to increase the percent by a random number… You can use the method I explained in the first reply, and then add it to a variable called (for example) “Damage”… then you can use an “impulse” node to get the knock back effect, plugging your damage to the strenght… You just need to try (with the help of math: you need to create basic functions like straight lines) with different combination of number, since you don’t get the desired ammount of knockback. Let me know if it works 