(Not for students who have taken ERG2011, 2012, 2013, 2014, 2015, 2018, MAE4070 or MAT2010.) This course introduces basic mathematical tools that are indispensable in modern economics. Topics include partial differentiation, implicit function method, optimization for multiple variable functions, and Lagrangian method. Economic applications are also covered, including equilibrium analysis, comparative statics, profit maximization, consumer demand, and dynamic analysis. Students should have knowledge of elementary differential and integral calculus.