A number of values of slices

I want to able to easy typ a number of slices, because stretching is not a value, it is only .siz() that is possible but than I don't know how many people would be into the car.
can there be an option to make a sliceValue?


what I do know is calculating the width, but that does not work out correctly when having several

so this formula I don't know how to create correct to calculate each time

 678 + (labelInput.text * 150),

thanks

Good idea - but no.