Inclusive multi-jet production is studied using proton-proton collisions at a center-of-mass energy of 7 TeV. The data sample corresponds to an integrated luminosity of 2.43 pb^(-1), and uses a subset of the data collected by the ATLAS detector in 2010. Measurements of multi-jet production cross sections with up to six jets are presented and compared to both leading-order predictions enhanced by a parton shower and next-to-leading-order calculations. Generally, agreement is found between data and leading-order and next-to-leading-order predictions. Regions of phase space or observables in which pure parton-shower simulations differ from the measurements are well described by leading-order calculations that combine matrix-element calculations with several outgoing partons in the final state to parton-shower simulations. Measurements compared to next-to-leading-order calculations are shown to be sensitive to the value of the strong coupling constant.