What are the three different approaches to calculating operating cash flow (OCF) discussed in the chapter?

The three different approaches to calculating operating cash flow (OCF) are the bottom-up approach, the top-down approach, and the tax shield approach.

The bottom-up approach starts with net income and adds back noncash expenses like depreciation. The top-down approach begins with sales and subtracts costs and taxes to arrive at OCF. The tax shield approach calculates OCF by considering the cash flow from operations adjusted for taxes and adding back the tax savings from depreciation.