This curriculum is an intermediate result of a research program exploring the application of detailed behavior analysis procedures to the problem of designing sequences of learning objectives. The research program, part of the Primary Education Project (PEP), is an attempt to develop a systematic method of specifying and validating learning hierarchies so that instructional programs can be designed which provide an optimal match for a child's natural sequence of acquisition. An operational definition of the number concept is proposed in the form of a set of eight behavioral objectives which, taken together, permit the inference that the child has an abstract concept of "number." Each behavioral objective is analyzed to identify both its component behaviors or skills and the prerequisite behaviors necessary for learning those components. Specific sequences of learning objectives are then proposed which are hypothesized to facilitate optimal learning by maximizing transfer from earlier to later objectives. A formalized "mastery" model is described in which children are tested to determine their entering level in the curriculum and are then passed on to higher level objectives on the basis of their demonstrated mastery of lower level ones. (JY)