The manual is intended to help school psychologists determine strengths and weaknesses, establish goals, and prescribe interventions for students with difficulties in mathematics, spelling, and written language. Research on sources of mathematical difficulties, theoretical bases, and hierarchies in mathematics is reviewed, procedures for formal and informal assessment (including task analysis and error pattern analysis) are discussed, and suggestions are offered for mathematics remediation. The section on spelling considers models, factors influencing performance, and specific spelling disabilities. The diagnosis of spelling problems is addressed, as is instruction/remediation based on assessment information. The final section focuses on written expression noting the sequence of skills, diagnostic considerations, and suggestions for remediation/instruction. Each section concludes with extensive appended material (e.g., check lists of skills and types of individualized instruction). (CL)