00444nam a2200133 a 450000500170000000800410001702000180005805000270007624500910010326000460019430000170024065000400025765000130029720140412111235.0001110s19uu    xx            00    eng d  a0-88336-811-0  aTR(GS 510.7bAd21 1981  aAdding whole numbers :blevel one: book 2 breaktrough math /cedited by Ann K. Tusing.  aSyracuse, NY :bNew Readers Press,c1978.  a64 p. ; ill.  aMathematics - - study and teachings  aaddition