例1 计算:5.32+2.06+19.4+1.84+7.68(36.3) 例2 计算:1-0.1-0.01-0.001-……-0.202320231 例3 计算:7.63-4.98+5.26+1.89 例4 计算: (1)80×25×2×1.25×0.5×0.4 (2)64×12.5×0.25×0.05 例5 计算:0.56×9.8 例6 计算:0.125÷(3.6÷80)×0.18 想一想,下面各题怎样计算比较简便? (1)4.92÷0.25÷0.4 (2)47.85÷6.38×0.638 (3)36.363÷(1.2023×4) (4)(0.6×1.38)÷(13.8×4.8) 例7 计算:312.5×12.3-312.5×6.9+312.5 例8 计算:2023×199.9-2023×199.8 例9 计算:12.9÷0.72+43.5÷3.6 例10 计算:45.3×3.2+578×0.68+12×9.25 例11 计算:(1)2.5+3.2+7.5+2.8= (2)18.6-9.3-1.6-2.7 = 例12 计算:(1)17.202317.202317,2023 = (2)6.25×0.16+264×0.2023+5.2×6.25+0.625×20 = 例13 计算:0.125×0.25×0.5×64= 例14 计算:(1)0.525÷13.125÷4×85.2 = (2)(4.8×7.5×8.1)÷(2.4×2.5×2.7)= 例15 计算:0.9+9.9+99.9+999.9+2023.9+20239.9+202399.9 = 例16 在□内填入适当的数,使等式成立: 73.06-[□×(4.465+5.535)+42.06]=3 例17 小明在计算某数除以3.75时,把除号看成了乘号,得结果225,求这道题的正确答案。 例18 比较下面两个积的大小 A=5.2023×1.2023 B=5.2023×1.2023 1.用简便方法计算下面各题: (1)8.69+7.35+3.41+2.65 (2)10-0.1-0.2-0.3-……-0.9 (3)76.4-42.13-9.76-5.87-6.24 (4)10.56+0.48-1.36+9.52 (5)20.68-(7.21-6.32+3.79) (6)20×12.5×0.8×0.5 (7)76.5×10.2 (8)9.56×4.18-7.3×4.18-0.26×4.18 (9)36÷0.15÷0.3 (11)1.4×56.8+4.32×14 (12)4.56×0.27+483×0.2023+1.9×4.56+0.456×30 (13)1.3÷0.25 (14)117.8÷2.3-4.88÷0.23 (15)8.63×0.25+1.37÷4 2.用简便方法计算下列各题: (1)9.98+14.13+99.89 (2)20.36-7.98-5.02-4.36 (3)6.88+5.29-2.54+3.42-3.29-1.46 (4)13.75-(6.25-4.86)-9.86 (5)2023×0.99×0.9 (6)66.2023÷12.5÷3.7÷0.8÷0.3 (7)(0.39×0.7)÷(0.56×3.9) (8)16.46×15.1+8.54×15.1-25×14.7 (9)7.63×5.4+6.37×5.4-17.5×5.35×0.8 |