I have a client who sells dog food. He offers several presentations of the product. For example, he sells 100 LBS sacks of dog food. But he also sells 1 LBS, 3 LBS, and 5 LBS bags of the same dog food. 

When he buys it from his supplier it comes on the 100 LB sacks, and what he does is that he opens 1 of the 100 LBS sack and he weighs and bags the 1,3 and 5 LBS bags. The price per pound varies according to the weight of the bag being sold, it´s cheaper if you buy the 100 LBS sack than if you buy a 5 LBS presentation. 

Is there an option on ODOO which I can use to do this? When I use a 100LBS sack to make 20 5LBS bags it should subtract from inventory the 100LBS sack and add the new 20 5LBS bags.

In my product catalogue I have them separated as different products:

• PURINA DOG FOOD - 100 LBS
• PURINA DOG FOOD - 5 LBS
• PURINA DOG FOOD - 3 LBS
• PURINA DOG FOOD - 1 LBS