TY - BOOK AU - Schoen,Harold L. AU - Zweng,Marilyn TI - Estimation and mental computation: 1986 yearbook T2 - Yearbook / National Council of Teachers of Mathematics SN - 0873532260 AV - QA1QA63 .N3 1986 U1 - 510 s511/.4�19 PY - 1986/// CY - Reston, Va. PB - National Council of Teachers of Mathematics KW - Problem solving KW - Estimation theory KW - Mental arithmetic ER -