You will need to specify the columns you want to insert values into. Please find the below mentioned sample SQL script where InventoryValue is the computed field.
CREATE TABLE dbo.Products
(
ProductID int IDENTITY (1,1) NOT NULL
, QtyAvailable smallint
, InventoryValue AS QtyAvailable * UnitPrice
, UnitPrice money
);
INSERT INTO dbo.Products (QtyAvailable, UnitPrice) VALUES (25, 2.00), (10, 1.5);
select * from dbo.Products