TY  - BOOK
AU  - Pennington,Bruce Frankiln
TI  - What Piaget's conservation of number task doesn't tell us about a childs understanding of numerical invariance
PY  - 1977///
CY  - Ann Arbor, Mich.
PB  - University Microfilms International
KW  - Number concept
KW  - Mathematical ability
N1  - Thesis (Ph.D.) - Duke University, 1977
ER  -