Table Relationships/Update Calc query and Subform Calculation

Hi,

I am having trouble trying to setup 2 tables. I am not sure of how they should be related. I have one table Inventory and one table Product Request Details. The Product Request Detail table contains
LB1, LB2, LB3, etc. each of these LB fields
has a Product 1, Product 2 within the Product Request Details table. The LBS and Ingredients should be linked to the Inventory table. When the number of LBS are entered for each Product within the Product Request Details table. I would like to run a query which would update the LBS(subtract) associated with each unique product within the inventory table. Am I conceptualizing this is the correct manner? Any other suggestions?

Also...

I would like to create a calculation field in my subform. The calc field will be the product of Total LBS from the main from and PERCENT from the subform (Total LBS * Percent). Step by step, how is this done?

Any help would be so appreciated.

Thanks,
Aricia

I appreciate any help. I will "pay it forward."

Thanks so much.

Which version of Access are you running?

S-