TY  - BOOK
AU  - TOMAS, FRANCISCO
ED  - National Council of teachers of Mathematics
TI  - Numeros racionales 
SN  - 9682400988
AV  - QA 248.3 T6551n 
CY  - Mexico 
PB  -  Trillas
KW  - 1. Aritmetica - Fundamentos
N1  - Traduccion de : Topics in mathematics for elementary school Teachers
ER  -