CFO - Indirect Method method, income, already, interest

jawz

I still don't get it. Please help. :-(

If you have the below info:
Net income was $850,000.
Depreciation expense was $200,000.
Interest paid was $100,000.
Income taxes paid were $50,000.

What's your CFO, using the indirect method?

The answer is $1,000,000 and the calculation is:
Cash flow from operations is ($850,000 + $200,000 – ($100,000 − $50,000)) = $1,000,000.

Why should we consider interest & income taxes here? Aren't they already factored in NI?