估算:905500-500900≈403553-205000≈505500-408900≈703543-205050≈803033-205010≈805500-508900≈
直接写出答数:0.57+0.43= 4.27﹣3.15= 15.6+0.04= 0.4﹣0.04=
计算并验算.23.66+6.34 60﹣37.56.
竖式计算.(带※的要验算)38.07+27.98 ※40﹣27.64 28.34+54.27100.1﹣38.64 34.08﹣15.94 ※34.2+18.9.
用竖式计算,并验算.48.5+47.25= ;20.8﹣6.48= .
列竖式计算:3.7+6.05= 8.25﹣4.9= 2.6+12.75= 36×45= 78×22= 87×21=