Arithmetic Teacher (1989-1990) Vol. 37, No. 6

  • Arithmetic Teacher (1989-1990) Vol. 37, No. 6

    .\'1 ATHEMATIC S E U lJ (: i\''";1~ 1 O.N, 't H H 0 UGH THE MID o :L E -GRAD E. S .. ~-~ .t; •• . .._. . . -. .. ' . ...~~~~~~.~~.....~~~~~~.~~.. • • ~-~~.. ~-• • ~.,. ~.,. VOLUME 37 NUMBER 6 FEBRUARY 1990 -----------SPATIAL SENSE -----------~ -:--~ __ ... ")11-..=--. . FOCUS ~S~(i.~~ . . ,.~ -. . .. Addison-Wesley Ma