In this work, we propose a simplified least squares formulation (SLSF) for dynamic material balancing in chemical processes, which are often described by differential-algebraic equations. We compare the SLSF with traditional techniques, such as steady state data reconciliation (SSDR) and Kalman filter (KF). We also modify the SLSF when its assumptions can't be totally satisfied in some practical settings. Using chemical systems examples, we demonstrate that the SLSF can well deal with the practical dynamic material balancing problems.