Story sums
Story sums, problem solving sums and detective sums all refer to the same thing.  These sums are language based.  It is imperative that you start exploring, investigating and playing with these kinds of sums as early as possible.  Many children who find the written word a challenge, find story sums very tricky when they are required to read them. This is because they have to read the sum, internalise it, choose the operation necessary – addition, subtraction, multiplication or division -  and then calculate the answer to the sum.