Elimination of non cash expenses (e.g. depreciation, amortization, impairment losses, bad debts written off, etc)
Removal of expenses to be classified elsewhere in the cash flow statement (e.g. interest expense should be classified under financing activities)
Elimination of non cash income (e.g. gain on revaluation of investments)
Removal of income to be presented elsewhere in the cash flow statement (e.g. dividend income and interest income should be classified under investing activities unless in case of for example an investment bank)
Working capital changes (e.g. an increase in trade receivables must be deducted to arrive at sales revenue that actually resulted in cash inflow during the period)