00578nam a2200193Ia 450000500170000000800410001704000190005804100120007708200130008910000180010224501020012026000380022230000160026044000430027650400190031965000150033870000210035385000100037420240529113343.0131103s9999    xx            000 0 und d  aLoreto College  aEnglish  a511bOSB  aOsborn, Roger  aUnderstanding the number systemcRoger Osborn, M Vere DeVault, Claude C Boyd and W Robert Houston  aColumbusbCharles E Merrillc1968  aviii,189p.   aMerrill's Mathematics Education Series  aIncludes index  aArithmetic  aDeVault, M Vere   aLCBED