Add a value to total field if radio box is selected

Hi, havn't used this for a while and have the following scenario:

https://form.jotformeu.com/60412416258349

Valentines offer - 2 meals £20. If they select this i want to add £20 to total order value, and when they select the dishes they want it doesnt add to the total (each dish is assigned a value). E.g. 2 mains, 1 starter, 1 side.

Also, would like the option to add extras on so if they do want to order more they can then select them and it will then add that to the total.

Any ideas?

 

Thanks

You need to assign a value to each option: https://www.jotform.com/help/301-How-to-Assign-Calculation-Value 

And if you want to gather the total, that can be done through the Form Calculation widget: https://www.jotform.com/help/259-How-to-Perform-Form-Calculation-Using-a-Widget 

Let us know if you need more help.

 

Thats great thanks, what about not totalling up the orders when they select
the menu items? i.e. i select this radio button, totals up to £20 then i
can select 4 items that do not add to the total order value?
...

You just need to make sure that the field the you do not need in your computation is not include in your calculations. You can check this sample cloned form that I have created: https://form.jotform.com/70403242483953. On the sample form, I am using the Product option on the calculation. Selecting any sub-product does not affect the calculations.

 

Do let us know if you need further assistance.
Regards.