What to product_sku on the details page of the product?

[antoniog360]

Hello everyone,
excuse my English, I'm Italian.
I noticed that the default on the details page of the product, at the top right, I mean the area that shows the values ​​that will be present in the cart dopoil click on the "Add to cart", there is the corresponding value for the field 'product_sku 'I have noticed, however, that it appears in your shopping cart!
I would like to show the value of 'product_sku' of the product that the user is viewing even before you press the button that adds it to your cart.
I think I understand that changes must be made within the code of the page but I do not understand which page is convolta in the view and if you need to define a new model or add code to an existing model.
Who can help me?
Thanks in advance.