How to add, multiply number variables in a Django template?

Question

The JS snippet I created relies on the forloop.counter variable being available within a {% for key, value in data.items %}..{% endfor %} tag.

Is there

Answer 1

I make the next in my template file carts.html

{% extends 'base.html'%} {% block contenido %}
Checkout
Subtotal + IVA: ${{ orden.sub_total }}
Envio:$ {{ orden.costo_envio }}
Total a pagar:$ {{ orden.sub_total|add:orden.costo_envio }}
{% endblock %}

where my view based function is:

def carrito_checkout(request):
    if 'cart_id' in request.session:
        orden_object, created = Orden.objects.get_or_new(request)
        if orden_object is None:
            return redirect('carrito:home')
        print(orden_object)
        context = {
            "orden": orden_object
        }

    return render(request, 'carrito_checkout.html', context=context)

For me this aproach works fine