心算。
3.18+1.82=97-36=4.8-2.9=54+9+16=
25×6=7.8+0.7=0.+0.4=36÷6×5=
6-2.3-2.7=39×2×5=25+75+18=55÷11×4=
3.15×100=270÷90=25×8=33÷11×4=
15×6=12×5=4-2.5=81÷9×8=
3.6+0.8=0.93+1.35=9.85-0.85=53+24-21=
5-1.5=0.6+1.73=3.7+1.13=0.37+0.03-0.1=
180÷5÷4=75÷100×1000=0.28×100÷10=10.38+0.62+2=