TY  - BOOK
AU  - Sawyer, W. W.
TI  - Vision in elementary  mathematics: Introducing mathematics 1 
U1  - 510   
PY  - 1964///
CY  - New York
PB  - Penguin Books
KW  - Mathematics
KW  - Elementary mathematics
KW  - Divisibility
KW  - Graphs
KW  - Fractions
ER  -