1、六年级简算题 4.2×4.2+0.42×58+42=42×0.42+42×0.58+42=42×(0.42+0.58+1)=42×2=842.7/25×103-7/25×2-7/25=7/25×(103-2-1)=7/25×100=283.2-1/2-1/3-1/6=2-(1/2+1/3+1/6)=2-1=14.88888×667+44444×666=88888×667+88888×333=88888×(667+333)=88888×1000=888880005.20042-20032=(2004+2003)×(2004-2003)=4007×1=40076.(567+345×566)/(567×345+222)=(567+345×566)/(566×345+345+222)=(567+345×566)/(566×345+567)=1。