One line of prior works designed rules (Mukherjee and Garain, 2008;Hosseini et al., 2014) or templates Zhou et al., 2015;Mitra and Baral, 2016) to map problems to expressions, where rules or templates are collected from training data.
the key to solving the problem is to reveal the underlying mathematical relations (such as addition and subtraction) among quantities, and then generate equations to find solutions.