五（上）西师版数学第一单元测试.2

五年级上册数学单元测试-1.小数乘法一、单选题1.5×3.14=（  ）A. 6                                       B. 12.56                                       C. 15.7                                       D. 812.把38.63的小数点移到最高位的右边，原数就（）。A. 扩大10倍                 B. 扩大100倍                 C. 缩小到原来的                 D. 缩小到原来的3.下面各式得数小于0.85的是（）。A. 0.85×1.01                                 B. 0.85×0.99                                 C. 0.85×14.下列算式中（  ）与2.3×2.4的积不同A. 0.23×24                                  B. 23×2.4                                  C. 230×0.0245.把3.95保留一位小数应是（ ）A. 3.9                                            B. 4.0                                            C. 46.1千克大豆可榨油0.13千克，1吨大豆可榨油（  ）A. 0.00013千克                          B. 13千克                          C. 130千克                          D. 1300千克7.一个不为0的数乘1.01，所得的积比这个数（  ）A. 大                                           B. 小                                           C. 相等8.4.995保留两位小数的近似值是（  ）A. 5.00                                         B. 4.99                                         C. 4.909.用竖式计算0.75×0.016=（  ）A. 0.012                                   B. 0.72                                   C. 2.45                                   D. 3.01510.一根铁丝长1.2cm，25根这样的铁丝，长________m．（  ）A. 30                                        B. 0.3                                        C. 3                                        D. 3000二、判断题11.判断：两个因数中共有四位小数，积的小数也一定是四位。12.判断对错．2.995精确到百分位是313.0.596保留两位小数是0.614.3.28×0.06的积中有四位小数。15.4.9699···保留三位小数约是4.970。三、填空题16.1.28与4.6相乘的积乘0.9,结果是________17.写出小面各小数的近似数保留一位小数4.59≈________             0.098≈________18.计算．             （1）0.307的4倍________（2）160的1.25倍________19.0.37×2.9=________0.56×0.08=________20.填空题（1）0.8×6＝________（2）0.12×4＝________（3）0.2×0.3＝________21.做表中的乘法题，尽可能灵活地计算．________22.计算：45.5÷38=________(得数保留两位小数)23.一种鲫鱼每千克5.5元，买3千克要________元．买1.2千克要________元．买0.8千克要________元24.2.4×101＝________25.乐福小学的篮球场是一个长88.6米、宽53.4米的长方形，这个篮球场的面积是（  ________ ）平方米。(得数保留一位小数)四、计算题26.写出下面的近似数．31.9≈（精确到个位） 4.202≈（精确到十分位）32900≈万524360950≈亿．五、解答题27.对下列数找出三对数，使它们的积等于这个数．例：0.36=4×0.09  0.36=1.2×0.3  0.36=0.18×24.528.有8台机器，每台重870千克，用两辆载重4吨的卡车，能一次运走吗?六、应用题29.求下面图形的面积．30.小红在计算一个数乘2.5时，忽略了2.5的小数点，得到的结果是75，正确的结果是多少？答案解析部分一、单选题1.【答案】C2.【答案】C3.【答案】B4.【答案】B5.【答案】B6.【答案】C7.【答案】A8.【答案】A9.【答案】A10.【答案】B二、判断题11.【答案】错误12.【答案】错误13.【答案】错误14.【答案】正确15.【答案】正确三、填空题16.【答案】5.299217.【答案】4.6；0.118.【答案】（1）1.228 （2）200 19.【答案】1.073；0.044820.【答案】（1）4.8（2）0.48（3）0.0621.【答案】98,0.98,9.8,0.098;5.6,0.056,0.56,0.0056;50.4,0.504,5.04,0.0504;148.4,1.484,14.84,0.1484;302.4,3.024,30.24,0.302422.【答案】1.2023.【答案】16.5；6.6；4.424.【答案】242.425.【答案】4731.2四、计算题26.【答案】解答：解：31.9≈32；4.202≈4.2；32900≈3万；524360950≈5亿五、解答题27.【答案】解：4.5=5×0.94.5=0.5×94.5=0.45×1028.【答案】870×8≈7200(千克)4×2=8(吨)=8000千克8000千克＞7200千克答：能一次运走六、应用题29.【答案】解:4.2×4.2=17.64(平方米)30.【答案】解：75÷25×2.5＝3×2.5＝7.5答：正确的结果是7.5