3.妈妈买了3把牙刷和4块毛巾,每把牙刷2.3元,每块毛巾3.2元.一共用了多少钱?
4.两辆汽车同时从A站向相反方向开出.甲车每小时行52.5千米,乙车每小时行62.2千米.经过4小时,两车相距多少千米?
期中测试题^答~`案
一、1.8.2的百分之十五; 2.0.54 1.8; 3.200×25+0.02×25; 4.21.07; 5.4时30分 138分 3.25时 3.4时; 6.32.34 0.9; 7.3.5 3.49 3.490; 8.2.078<2.078078……<2.07878……
二、1.×; 2.×; 3.×; 4.×; 5.×; 6.×
三、1.C; 2.C; 3.C; 4.B
四、1. 12.5×4.64×0.08 23.13+25×0.16+1.87
=12.5×0.08×4.64 =(23.13+1.87)+25×4×0.04
=1×4.64 =25十100×0.04
=4.64 =25+4
=29
2.6.3; 62; 4.68; 40.5
3. 1-(6.75-3.5)÷13 〔4.25-4.25×(475-3.95)〕÷1.7
=1-3.25÷13 =(4.25-4.25×0.8)÷1.7
=1-0.25 =4.25×(1-0.8)÷1.7
=0.75 =4.25×0.2÷1.7
=0.85÷1.7
=0.5
五、1. (6.5+3.2)×(6.5-3.2) 2. (34.17÷1.7+1.6)×03
=9.7×3.3 =(20.1+1.6)×0.3
=32.01 =21.7×0.3
=6.51
六、1.(764.5×8)÷2.5=16(车)
2.6×15÷(615)=20(天)
3.2.3×3+3.2×4=19.7(元)
4.(52.5+62.2)×4=458.8(千米)