ABSTRACT
One type of classroom exercise that involves the use of numbers is the solving of arithmetic problems. Arithmetic problems are part of the stable school diet and students are known to encounter a whole host of difficulties with them. This chapter summarizes the state of the art in this area and attempts to form a coherent picture of the development of problem-solving strategies involving numerical operations. Given the data available at the current time, this overview will be restricted to additive problems: problems that can be solved by either addition or subtraction.
