Auto-calculate 2 Column That Contains Numbers And Words Words

I've been using conventional method to do this and it's time consuming. I would like to total up 2 column. A multiply B to be exact. Below are some examples:

Table 1 - Before totaling up:

Quantity
Product
5
2 x Button A White
3
4 x Button B Pink
4
5 x Ribbon A Black
2
3 x Thread A White
6
2 x Cloth A Blue

Table 2 - After totaling up:

Quantity
Product
10
Button A White
12
Button B Pink
20
Ribbon A Black
6
Thread A White
12
Cloth A Blue

I need to have the sum of the "Quantity" multiply "Product". Or in short A x B.
And the end result need to have the number and "x" sign removed while keeping on the the products names. (2 x ) Take note it's "number" space "symbol" space.