Thats Par value that has nothing to do "Book value". Par value is just a booking number. It hardly ever changes (read never). It has reallllllllly nothing to do with valuaing a company.
In accounting, book value or carrying value is the value of an asset according to its balance sheet account balance. For assets, the value is based on the original cost of the asset less any depreciation, amortization or impairment costs made against the asset. Traditionally, a company's book value is its total assets minus intangible assets and liabilities.[1][2] However, in practice, depending on the source of the calculation, book value may variably include goodwill, intangible assets, or both.[3] When intangible assets and goodwill are explicitly excluded, the metric is often specified to be "tangible book value".[citation needed]
Use previous post: the companies financial report to calc book value.