000 00297nam a2200121Ia 4500
100 _aBallard, Philip Boswood
942 _cBK
654 _a
245 _aTeaching the essentials of arithmetic
260 _aLondon
_bUniversity of London Press
_c1944
082 _a375.511
300 _bHb
_axxiv,260
999 _c403694
_d403694
041 _aeng