ArmstrongJ. R., & SchmidtH. (1972). Simple materials for teaching early number concepts to trainable-level mentally retarded pupils. Arithmetic Teacher, 19, 149–153.
2.
ConnollyA. (1973). Research in mathematics education and the mentally retarded. Arithmetic Teacher, 20, 491–497.
3.
EasleyJ., & EasleyE. (1982) Math can be natural: Kitamaeno priorities introduced to American teachers. Urbana-Champaign, IL: Committee on Culture and Cognition, University of Illinois.
4.
FlexerR. J. (1986). The power of 5: The step before the power of 10. Arithmetic Teacher, 34, 5–9.
5.
GelmanR., & GallistelC. R. (1978). The child's understanding of number. Cambridge, MA: Harvard University Press.
6.
JensenA. R. (1970). A theory of primary and secondary familial mental retardation. In EllisN. R. (Ed.), International review of research in mental retardation (Vol. 4, pp. 33–105). New York: Academic Press.
7.
MyersA. C., & ThorntonC. A. (1977). The learning disabled child—Learning the basic facts. Arithmetic Teacher, 25, 46–50.
8.
RebecL. (1972). A case against teaching mathematical concepts to slow-learning children. Arithmetic Teacher, 19, 333–334.
9.
StakeB. (1980). Clinical studies of counting problems with primary school children. Unpublished doctoral dissertation, University of Illinois at Urbana-Champaign.
10.
ThompsonC., & Van de WalleJ. (1984). The power of ten. Arithmetic Teacher, 32, 6–11.
11.
VitelloS. (1976). Quantitative abilities of mentally retarded children. Education and Training of the Mentally Retarded, 11, 125–129.
12.
WirtzR. (1980. New beginnings. Monterey, CA: Curriculum Development Associates.
