Keep parameters behind the call
DATA(sum) = add_two_numbers( value_1 = 5
value_2 = 6 ).When this makes the lines very long, you can break the parameters into the next line:
DATA(sum) = add_two_numbers(
value_1 = round_up( input DIV 7 ) * 42 + round_down( 19 * step_size )
value_2 = VALUE #( ( `Calculation failed with a very weird result` ) ) ).