Multiple “Add to cart” buttons with quantities specified

Question

Hi I would like to have three "Add to cart" buttons which add specified quantities for my products and remove the input field.

So rather than [qty input] [Add to card]

I'd like

[Add a single to cart]

[Add 6 to cart]

[Add 12 to cart]

Wondering on the best way to do this, I would also like to implement this on the product listing.

Thanks