Add To Cart does not allow me to enter the quantity of the product, for example 0.50. how can I enter quantities of the product in decimals

You cannot enter partial quantities.

The store will not calculate a ‘part’ of a product.

For example the following is incorrect:

Product: rice
Price: 1 per pound
Options: none
Quantity: 0.5

The following example is correct:

Product: rice
Options:

  1. 0.5 pound at 0.50

  2. 1 pound at 1

  3. 1.5 pound at 1.5

  4. 2 pound at 2

Quantity: 1 of the 0.50 option

P.s. This is not a Corvid related so you may want to contact Wix Customer Support for help on how to properly enter products, as I suspect your post will get closed or deleted soon.