X0306 4 2013-02-04 0001364742 BlackRock Inc. BLK 0001233157 DAMMERMAN DENNIS D BLACKROCK, INC. 55 EAST 52ND STREET NEW YORK NY 10055 1 Shares Of Common Stock (par Value $0.01 Per Share) 2013-02-04 4 S 0 1794 234.4081 D 3367 D This transaction was executed in multiple trades at prices ranging from $234.28 to $234.49. The price reported represents the weighted average sale price of these trades. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the shares sold at each separate price. /s/ Daniel R. Waltcher as Attorney-in-Fact for Dennis D. Dammerman 2013-02-06