Set variable to sum of two numbers or to sum of two other variables parsed as number

[Lucraft3000]

Hello.

I have problems to define a variable to the sum of two numbers or two other variables:

command /calculator [<number>] [<number>]:
trigger:

set {_1} to a random number between 1 and 10
set {_2} to a random number between 1 and 10
set {_3} to sum of {_1} and {_2}

I hope you can help me.
Best regards.

 

[Mattia]

set {_3} to {_1} + {_2}

The other lines were ok, instead of sum of x and y you have to put x + y