The authors discuss the challenges related to solving math word problems. Then, they discuss each of the addition and subtraction word problem schemas and provide a framework for introducing these schemas to students who experience difficulty with math.
Stevens, E. A., & Powell, S. R. (2016). Unpacking word problems for diverse learners: A guide to using schemas. Childhood Education, 92, 86–91. doi:10.1080/00094056.2016.1134253