<br><strong><span>一．解答题（共3小题，满分42分）</span></strong><br><br><span>1．（10分）用简便方法计算</span><br><br><span>82</span><span>+</span><span>（555</span><span>+</span><span>28）</span><br><br><span>16</span><span>×</span><span>25 </span><br><br><span>720</span><span>÷</span><span>16</span><span>÷</span><span>5．</span><br><br><span>2．（24分）怎样算简便就怎样算</span><br><br><span>153</span><span>+</span><span>86</span><span>+</span><span>47 </span><br><br><span>19</span><span>×</span><span>15</span><span>×</span><span>4 </span><br><br><span>598</span><span>÷</span><span>（43﹣17）</span><br><br><span>436﹣158﹣42 </span><br><br><span>（91﹣63）</span><span>×</span><span>15 </span><br><br><span>640</span><span>÷</span><span>5</span><span>÷</span><span>16．</span><br><br><span>3．（8分）列式计算：</span><br><br><span>（1）368加上14除392的商，和是多少？</span><br><br><span>（2）16个625与最大的四位数相差多少？</span><br><br><strong><span>二．填空题（共7小题，满分15分）</span></strong><br><br><span>4．（3分）目前，我国香港地区的总面积是十亿五千二百万平方米，改写成“万”作单位的数写作</span><span style="text-decoration:underline"><span> </span></span><span>平方米，省略“亿”后面的尾数约是</span><span style="text-decoration:underline"><span> </span></span><span>平方米．</span><br><br><span>5．（2分）</span><div><br></div><div><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228154829.png?m=0.04046378364055303"><br></div><div><br><span>6．（1分）正方形网格中，小格的顶点叫做格点．如图，A、B两点在正方形网格的格点上，每个方格都是边长为1的正方形．点C也在格点上，且</span><span>△</span><span>ABC为等腰三角形，则符合条件的格点C共有</span><span style="text-decoration:underline"><span> </span></span><span>个．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228154950.png?m=0.2127219963800211"><br><br><span>7．（3分）用10倍的放大镜看一个40°的角，看到的角是</span><span style="text-decoration:underline"><span> </span></span><span>度．</span><br><br><span>8．（3分）圆是一个轴对称图形，它有</span><span style="text-decoration:underline"><span> </span></span><span>条对称轴．圆的周长与直径的比值，我们称之为</span><span style="text-decoration:underline"><span> </span></span><span>．</span><br><br><span>9．（1分）比25的30倍少20的数是</span><span style="text-decoration:underline"><span> </span></span><span>．</span><br><br><span>10．（2分）840</span><span>÷</span><span>8</span><span>÷</span><span>4=840</span><span>÷</span><span>（8</span><span>÷</span><span>4）</span><span style="text-decoration:underline"><span> </span></span><span>．</span><br><br><strong><span>三．选择题（共4小题，满分8分，每小题2分）</span></strong><br><br><span>11．（2分）9310</span><span>÷</span><span>7这道除法算式，当被除数增加4个7，不用计算就知道商一定增加（ ）</span><br><br><span>A．4</span><span></span><span>B．7</span><span></span><span>C．28</span><br><br><span>12．（2分）一列火车由A城开到B城行驶了3小时，返回时车速每小时减少10公里，则多行驶了半小时，那么A、B两地相距的公里数是（ ）</span><br><br><span>A．345</span><span></span><span>B．180</span><span></span><span>C．240</span><span></span><span>D．210</span><br><br><span>13．（2分）用一副三角尺像如图那样拼出一个钝角，这个钝角是多少度？（ ）</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155029.png?m=0.5603954252837191"><br><br><span>A．150°</span><span></span><span>B．135°</span><span></span><span>C．120°</span><br><br><span>14．（2分）</span><span style="text-decoration:underline"><span> </span></span><span>能量出它的长度，</span><span style="text-decoration:underline"><span> </span></span><span>没有端点，</span><span style="text-decoration:underline"><span> </span></span><span>有一端可以无限延长．</span><br><br><strong><span>四．操作题（共1小题，满分6分，每小题6分）</span></strong><br><br><span>15．（6分）在方格纸上按要求画出图形．</span><br><br><span>（1）把图中圆的直径放大到原来的2倍，画出这个圆．</span><br><br><span>（2）在放大后的圆里画一个最大的正方形．</span><br><br><span>（3）最后画出这个组合图形的所有对称轴．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228152050.png"><br><br><strong><span>五．解答题（共1小题，满分2分，每小题2分）</span></strong><br><br><span>16．（2分）算一算，如图中，</span><span>∠</span><span>1=60°，</span><span>∠</span><span>2是直角，求</span><span>∠</span><span>3，</span><span>∠</span><span>4，</span><span>∠</span><span>5各是多少度．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155130.png?m=0.9489994770486743"><br><br><strong><span>六．解答题（共5小题，满分24分）</span></strong><br><br><span>17．（5分）要把968个鸡蛋装盒，每盒装18个，48个盒子够不够？</span><br><br><span>18．（5分）小芳家距她的姑姑家有195千米，她坐的汽车平均每小时行驶65千米，她到姑姑家要多少小时？</span><br><br><span>19．（5分）小明看一本312页的故事书，每天看12页，看了6天，剩下的还要看几天？</span><br><br><span>20．（5分）王军的张数是李明张数的3倍，如果王军拿60张邮票送给李明，两人的邮票张数一样多，王军有邮票多少张？（列方程解）</span><br><br><span>21．（4分）一辆汽车从甲地开往乙地，前2小时行驶了136千米，照这样的速度行完全程需用12小时，甲乙两地相距多少千米？</span><br><br><strong><span>七．计算题（共2小题，满分3分）</span></strong><br><br><span>22．（1分）简便计算．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/2018122815528.png?m=0.8255493565601075"><br><br><span>23．（2分）参加运动会的女运动员有120人，比男运动员的2倍少6人．参加运动会的男运动员有多少人？</span><span><br clear="all" style="page-break-before:always"></span><br><br><div style="text-align: center;"><strong><font color="#38761d">2019年小学四年级数学上册期末考试试卷参考答案与试题解析</font></strong></div><br><strong><span>一．解答题（共3小题，满分42分）</span></strong><br><br><span>1．（10分）用简便方法计算</span><br><br><span>82</span><span>+</span><span>（555</span><span>+</span><span>28）</span><br><br><span>16</span><span>×</span><span>25 </span><br><br><span>720</span><span>÷</span><span>16</span><span>÷</span><span>5．</span><br><br><span>【分析】</span><span>（1）利用加法交换律和结合律简算；</span><br><br><span>（2）把16=4</span><span>×</span><span>4，按照乘法结合律简算；</span><br><br><span>（3）利用除法的性质简算．</span><br><br><span>【解答】</span><span>解：（1）82</span><span>+</span><span>（555</span><span>+</span><span>28）</span><br><br><span>=555</span><span>+</span><span>（82</span><span>+</span><span>28）</span><br><br><span>=555</span><span>+</span><span>110</span><br><br><span>=665；</span><br><br><br><span>（2）16</span><span>×</span><span>25 </span><br><br><span>=4</span><span>×</span><span>（4</span><span>×</span><span>25）</span><br><br><span>=4</span><span>×</span><span>100</span><br><br><span>=400；</span><br><span> </span><br><br><span>（3）720</span><span>÷</span><span>16</span><span>÷</span><span>5</span><br><br><span>=720</span><span>÷</span><span>（16</span><span>×</span><span>5）</span><br><br><span>=720</span><span>÷</span><span>80</span><br><br><span>=9．</span><br><br><span>【点评】</span><span>整数混合运算的关键是抓住运算顺序，正确运用运算定律简算．</span><br><br><span>2．（24分）怎样算简便就怎样算</span><br><br><span>153</span><span>+</span><span>86</span><span>+</span><span>47 </span><br><br><span>19</span><span>×</span><span>15</span><span>×</span><span>4 </span><br><br><span>598</span><span>÷</span><span>（43﹣17）</span><br><br><span>436﹣158﹣42 </span><br><br><span>（91﹣63）</span><span>×</span><span>15 </span><br><br><span>640</span><span>÷</span><span>5</span><span>÷</span><span>16．</span><br><br><span>【分析】</span><span>（1）按照加法交换律计算；</span><br><br><span>（2）按照乘法结合律计算；</span><br><br><span>（3）先算小括号里面的减法，再算除法；</span><br><br><span>（4）按照减法的性质进行简算；</span><br><br><span>（5）先算小括号里面的减法，再算括号外面的乘法；</span><br><br><span>（6）按照除法的性质进行简算．</span><br><br><span>【解答】</span><span>解：（1）153</span><span>+</span><span>86</span><span>+</span><span>47 </span><br><br><span>=153</span><span>+</span><span>47</span><span>+</span><span>86</span><br><br><span>=200</span><span>+</span><span>86</span><br><br><span>=286</span><br><br><br><span>（2）19</span><span>×</span><span>15</span><span>×</span><span>4 </span><br><br><span>=19</span><span>×</span><span>（15</span><span>×</span><span>4）</span><br><br><span>=19</span><span>×</span><span>60</span><br><br><span>=1140</span><br><br><br><span>（3）598</span><span>÷</span><span>（43﹣17）</span><br><br><span>=598</span><span>÷</span><span>26</span><br><br><span>=23</span><br><br><br><span>（4）436﹣158﹣42 </span><br><br><span>=436﹣（158</span><span>+</span><span>42）</span><br><br><span>=436﹣200</span><br><br><span>=236</span><br><br><br><span>（5）（91﹣63）</span><span>×</span><span>15 </span><br><br><span>=28</span><span>×</span><span>15</span><br><br><span>=420</span><br><br><br><span>（6）640</span><span>÷</span><span>5</span><span>÷</span><span>16</span><br><br><span>=640</span><span>÷</span><span>（5</span><span>×</span><span>16）</span><br><br><span>=640</span><span>÷</span><span>80</span><br><br><span>=8</span><br><br><span>【点评】</span><span>本题考查了四则混合运算，注意运算顺序和运算法则，灵活运用所学的运算定律进行简便计算．</span><br><br><span>3．（8分）列式计算：</span><br><br><span>（1）368加上14除392的商，和是多少？</span><br><br><span>（2）16个625与最大的四位数相差多少？</span><br><br><span>【分析】</span><span>（1）先用392除以14求出商，再用368加上求出的商即可；</span><br><br><span>（2）16个625，即为625</span><span>×</span><span>16，最大的四位数是9999，用求出的积减去9999即可求解．</span><br><br><span>【解答】</span><span>解：（1）368</span><span>+</span><span>392</span><span>÷</span><span>14</span><br><br><span>=368</span><span>+</span><span>28</span><br><br><span>=396</span><br><br><span>答：和是396．</span><br><br><br><span>（2）625</span><span>×</span><span>16﹣9999</span><br><br><span>=10000﹣9999</span><br><br><span>=1</span><br><br><span>答：相差1．</span><br><br><span>【点评】</span><span>这类型的题目要分清楚数量之间的关系，先求什么再求什么，找清列式的顺序，列出算式求解．</span><br><br><strong><span>二．填空题（共7小题，满分15分）</span></strong><br><br><span>4．（3分）目前，我国香港地区的总面积是十亿五千二百万平方米，改写成“万”作单位的数写作</span><span style="text-decoration:underline"><span> 10 5200 0000 </span></span><span>平方米，省略“亿”后面的尾数约是</span><span style="text-decoration:underline"><span> 11亿 </span></span><span>平方米．</span><br><br><span>【分析】</span><span>根据整数的写法，从高位到低位，一级一级地写，哪一个数位上一个单位也没有，就在那个数位上写0，即可写出此数；省略“亿”后面的尾数就是四舍五入到亿位，就是把亿位后的千万位上的数进行四舍五入，再在数的后面写上“亿”字．</span><br><br><span>【解答】</span><span>解：十亿五千二百万写作：10 5200 0000；</span><br><br><span>10 5200 0000</span><span>≈</span><span>11亿．</span><br><br><span>故答案为：10 5200 0000，11亿．</span><br><br><span>【点评】</span><span>本题主要考查整数的写法、改写和求近似数．注意改写和求近似数时要带计数单位．</span><br><br><span>5．（2分）</span><br><table border="0" cellspacing="0" style="border:none;mso-padding-alt: ;"><tbody><tr><td style="border-right:none;border-none;border-bottom:none;"><br><span>3500立方分米=</span><span style="text-decoration:underline"><span> 3.5 </span></span><span>立方米</span><br></td><td style="border-right:none;border-none;border-bottom:none;"><br><span>0.8立方分米=</span><span style="text-decoration:underline"><span> 800 </span></span><span>立方厘米</span><br></td></tr><tr><td style="border-right:none;border-none;border-bottom:none;"><br><span>83立方厘米=</span><span style="text-decoration:underline"><span> 83 </span></span><span>毫升</span><br></td><td style="border-right:none;border-none;border-bottom:none;"><br><span>40升=</span><span style="text-decoration:underline"><span> 40000 </span></span><span>立方厘米</span><br></td></tr></tbody></table><br><span>【分析】</span><span>（1）低级单位立方分米化高级单位立方米除以进率1000．</span><br><br><span>（2）高级单位立方分米化低级单位立方厘米乘进率1000．</span><br><br><span>（3）立方厘米与升是同一级单位，二者互化数值不变．</span><br><br><span>（4）高级单位升化低级单位立方厘米乘进率1000．</span><br><br><span>【解答】</span><span>解：（1）3500立方分米=3.5立方米；</span><br><br><span>（2）0.8立方分米=800立方厘米；</span><br><br><span>（3）83立方厘米=83毫升；</span><br><br><span>（4）40升=40000立方厘米．</span><br><br><span>故答案为：3.5，800，83，40000．</span><br><br><span>【点评】</span><span>此题是考查体积（容积）的单位换算．单位换算首先要弄清是由高级单位化低级单位还是由低级单位化高级单位，其次记住单位间的进率．</span><br><br><span>6．（1分）正方形网格中，小格的顶点叫做格点．如图，A、B两点在正方形网格的格点上，每个方格都是边长为1的正方形．点C也在格点上，且</span><span>△</span><span>ABC为等腰三角形，则符合条件的格点C共有</span><span style="text-decoration:underline"><span> 9 </span></span><span>个．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155355.png?m=0.46325110070475195"><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155452.png?m=0.5195933168761624"><br><br><span>【解答】</span><span>解：根据分析，</span><br><br><span>（1）如果AB作底的话，符合条件的格点C共有5个．</span><br><br><span>（2）如果AB作腰的话，符合条件的格点C共有4个．</span><br><br><span>5</span><span>+</span><span>4=9（个）</span><br><br><span>故答案为：9．</span><br><br><span>【点评】</span><span>解答此题的关键是分两种情况解答：AB作底和AB作腰．</span><br><br><span>7．（3分）用10倍的放大镜看一个40°的角，看到的角是</span><span style="text-decoration:underline"><span> 40 </span></span><span>度．</span><br><br><span>【分析】</span><span>角的大小是指两边张开的大小，与两条边的分离程度有关，用放大10倍的放大镜看一个40°的角，也就是把边变长了，而两边张开的大小没变，即角的度数没变．</span><br><br><span>【解答】</span><span>解：用一个10倍的放大镜看一个20度的角，这个角是40度；</span><br><br><span>故答案为：40．</span><br><br><span>【点评】</span><span>此题主要考查角的大小只与角两边张开的大小，与两条边的分离程度有关，与边的长度无关．</span><br><br><span>8．（3分）圆是一个轴对称图形，它有</span><span style="text-decoration:underline"><span> 无数 </span></span><span>条对称轴．圆的周长与直径的比值，我们称之为</span><span style="text-decoration:underline"><span> 圆周率 </span></span><span>．</span><br><br><span>【分析】</span><span>根据圆的对称性和圆周率的定义直接填空即可．</span><br><br><span>【解答】</span><span>解：圆是一个轴对称图形，它有 无数条对称轴．圆的周长与直径的比值，我们称之为 圆周率．</span><br><br><span>故答案为：无数，圆周率．</span><br><br><span>【点评】</span><span>本题考查了圆的轴对称性和圆周率的意义．</span><br><br><span>9．（1分）比25的30倍少20的数是</span><span style="text-decoration:underline"><span> 730 </span></span><span>．</span><br><br><span>【分析】</span><span>先用25乘30求出25的30倍，然后再减去20即可．</span><br><br><span>【解答】</span><span>解：25</span><span>×</span><span>30﹣20</span><br><br><span>=750﹣20</span><br><br><span>=730</span><br><br><span>答：是730．</span><br><br><span>故答案为：730．</span><br><br><span>【点评】</span><span>本题关键是理解倍数关系：已知一个数，求它的几倍是多少用乘法求解．</span><br><br><span>10．（2分）840</span><span>÷</span><span>8</span><span>÷</span><span>4=840</span><span>÷</span><span>（8</span><span>÷</span><span>4）</span><span style="text-decoration:underline"><span> </span></span><span style="text-decoration:underline"><span>×</span></span><span style="text-decoration:underline"><span> </span></span><span>．</span><br><br><span>【分析】</span><span>一个数连续除以两个数，等于除以这两个数的积，840</span><span>÷</span><span>8</span><span>÷</span><span>4=840</span><span>÷</span><span>（8</span><span>×</span><span>4）．</span><br><br><span>【解答】</span><span>解：根据除法的性质知：840</span><span>÷</span><span>8</span><span>÷</span><span>4=840</span><span>÷</span><span>（8</span><span>×</span><span>4），</span><br><br><span>所以840</span><span>÷</span><span>8</span><span>÷</span><span>4=840</span><span>÷</span><span>（8</span><span>÷</span><span>4）错误．</span><br><br><span>故答案为：</span><span>×</span><span>．</span><br><br><span>【点评】</span><span>本题主要考查了学生根据除法的性质解答问题的能力．</span><br><br><strong><span>三．选择题（共4小题，满分8分，每小题2分）</span></strong><br><br><span>11．（2分）9310</span><span>÷</span><span>7这道除法算式，当被除数增加4个7，不用计算就知道商一定增加（ ）</span><br><br><span>A．4</span><span></span><span>B．7</span><span></span><span>C．28</span><br><br><span>【分析】</span><span>因为被除数增加4个7，而4个7除以除数7是4，所以商一定增加4．</span><br><br><span>【解答】</span><span>解：因为被除数增加4个7，而4个7除以除数7是4，所以商一定增加4．</span><br><br><span>故选：A．</span><br><br><span>【点评】</span><span>本题主要考查了除法算式里，被除数增加几个除数，商就增加几．</span><br><br><span>12．（2分）一列火车由A城开到B城行驶了3小时，返回时车速每小时减少10公里，则多行驶了半小时，那么A、B两地相距的公里数是（ ）</span><br><br><span>A．345</span><span></span><span>B．180</span><span></span><span>C．240</span><span></span><span>D．210</span><br><br><span>【分析】</span><span>此题可用方程解答，设去时每小时行x公里，3x=3.5（x﹣10），解方程求得x，然后把x代入方程任一边，即可求出A、B两地相距的公里数．</span><br><br><span>【解答】</span><span>解：设去时每小时行x公里，由题意得</span><br><br><span> 3x=3.5（x﹣10），</span><br><br><span> 3x=3.5x﹣35，</span><br><br><span>0.5x=35，</span><br><br><span> x=70；</span><br><br><br><span>A、B两地相距：</span><br><br><span>3x=3</span><span>×</span><span>70=210（公里）；</span><br><br><span>答：A、B两地相距210公里．</span><br><br><span>故选：D．</span><br><br><span>【点评】</span><span>根据路程相等列方程，求出原来火车的速度是解答此题的关键．</span><br><br><span>13．（2分）用一副三角尺像如图那样拼出一个钝角，这个钝角是多少度？（ ）</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155029.png?m=0.5603954252837191"><br><br><span>A．150°</span><span></span><span>B．135°</span><span></span><span>C．120°</span><br><br><span>【分析】</span><span>用的是三角尺90°的角和45°的角，二者相加就是所拼成的角的度数．</span><br><br><span>【解答】</span><span>解：90°</span><span>+</span><span>45°=135°．</span><br><br><span>故选：B．</span><br><br><span>【点评】</span><span>本题是考查图形的拼组、角的度量．利用三角板可以作出的度数有：15°30°45°60°75°90°105°120°135°150°180°等，动手拼组一下．</span><br><br><span>14．（2分）</span><span style="text-decoration:underline"><span> 线段 </span></span><span>能量出它的长度，</span><span style="text-decoration:underline"><span> 直线 </span></span><span>没有端点，</span><span style="text-decoration:underline"><span> 射线 </span></span><span>有一端可以无限延长．</span><br><br><span>【分析】</span><span>根据直线、射线和线段的含义：线段有2个端点，有限长，可以度量；射线有一个端点，无限长；直线无端点，无限长；进而解答即可．</span><br><br><span>【解答】</span><span>解：线段能量出它的长度，直线没有端点，射线有一端可以无限延长；</span><br><br><span>故答案为：线段，直线，射线．</span><br><br><span>【点评】</span><span>此题应根据直线、射线和线段的含义进行解答．</span><br><br><strong><span>四．操作题（共1小题，满分6分，每小题6分）</span></strong><br><br><span>15．（6分）在方格纸上按要求画出图形．</span><br><br><span>（1）把图中圆的直径放大到原来的2倍，画出这个圆．</span><br><br><span>（2）在放大后的圆里画一个最大的正方形．</span><br><br><span>（3）最后画出这个组合图形的所有对称轴．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228152050.png"><br><br><span>【分析】</span><span>（1）图中圆的直径是2格，根据图形放大与缩小的意义，画一直径是4格的圆，这个圆就是原图直径放大2倍的圆．</span><br><br><span>（2）以放大后的圆的直径为对角线所画的正方形最大．</span><br><br><span>（3）这个组合图形有4条对称轴，即过正方形两对角线的直线，过正方形对边中点的直线．</span><br><br><span>【解答】</span><span>解：（1）把图中圆的直径放大到原来的2倍，画出这个圆（下图红色部分）：</span><br><br><span>（2）在放大后的圆里画一个最大的正方形（下图绿色部分）：</span><br><br><span>（3）最后画出这个组合图形的所有对称轴（下图蓝色虚线）：</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155636.png?m=0.7534253157019402"><br><br><span>【点评】</span><span>此题考查的知识有：图形的放大与缩小；画圆；作圆内最大的正方形；确定轴对称图形对称轴的条数与位置．</span><br><br><strong><span>五．解答题（共1小题，满分2分，每小题2分）</span></strong><br><br><span>16．（2分）算一算，如图中，</span><span>∠</span><span>1=60°，</span><span>∠</span><span>2是直角，求</span><span>∠</span><span>3，</span><span>∠</span><span>4，</span><span>∠</span><span>5各是多少度．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155130.png?m=0.9489994770486743"><br><br><span>【分析】</span><span>直角是90度，平角是180度，观察图发现</span><span>∠</span><span>1、</span><span>∠</span><span>2和</span><span>∠</span><span>3构成一个平角，用180度减去</span><span>∠</span><span>1和</span><span>∠</span><span>2的度数和，即可求出</span><span>∠</span><span>3的度数；同理可以求出</span><span>∠</span><span>4、</span><span>∠</span><span>5的度数．</span><br><br><span>【解答】</span><span>解：</span><span>∠</span><span>3=180°﹣（</span><span>∠</span><span>1</span><span>+∠</span><span>2）</span><br><br><span>180°﹣（60°</span><span>+</span><span>90°）</span><br><br><span>=180°﹣150°</span><br><br><span>=30°；</span><br><br><br><span>∠</span><span>4=180°﹣（</span><span>∠</span><span>2</span><span>+∠</span><span>3）</span><br><br><span>=180°﹣（90°</span><span>+</span><span>30°）</span><br><br><span>=180°﹣120°</span><br><br><span>=60°</span><br><br><br><span>∠</span><span>5=180°﹣</span><span>∠</span><span>4</span><br><br><span>=180°﹣60°</span><br><br><span>=120°</span><br><br><span>答：</span><span>∠</span><span>3是30度，</span><span>∠</span><span>4是60度，</span><span>∠</span><span>5是120度．</span><br><br><span>【点评】</span><span>解决本题熟知平角、直角的度数，找出哪些角可以构成平角．</span><br><br><strong><span>六．解答题（共5小题，满分24分）</span></strong><br><br><span>17．（5分）要把968个鸡蛋装盒，每盒装18个，48个盒子够不够？</span><br><br><span>【分析】</span><span>每盒装18个，48个盒子可以装48个18，用48乘18求出可以装的总数量，再与968比较即可求解．</span><br><br><span>【解答】</span><span>解：48</span><span>×</span><span>18=864（个）</span><br><br><span>864</span><span>＜</span><span>968</span><br><br><span>答：48个盒子不够．</span><br><br><span>【点评】</span><span>本题先根据乘法的意义求出48个盒子可以装鸡蛋的个数，再比较求解．</span><br><br><span>18．（5分）小芳家距她的姑姑家有195千米，她坐的汽车平均每小时行驶65千米，她到姑姑家要多少小时？</span><br><br><span>【分析】</span><span>已知小芳家距她的姑姑家有195千米，她坐的汽车平均每小时行驶65千米，用路程除以速度即得她到姑姑家要多少小时．</span><br><br><span>【解答】</span><span>解：195</span><span>÷</span><span>65=3（小时）．</span><br><br><span>答：她到姑姑家需要3小时．</span><br><br><span>【点评】</span><span>本题为较为简单的行程问题，体现了行程问题的基本关系式：路程</span><span>÷</span><span>速度=时间．</span><br><br><span>19．（5分）小明看一本312页的故事书，每天看12页，看了6天，剩下的还要看几天？</span><br><br><span>【分析】</span><span>由题意可知，前6天一共看了：12</span><span>×</span><span>6=72页，则还剩下312﹣72=240页，剩下的还要240</span><span>÷</span><span>12=20天看完．</span><br><br><span>【解答】</span><span>解：（312﹣12</span><span>×</span><span>6）</span><span>÷</span><span>12</span><br><br><span>=（312﹣72）</span><span>÷</span><span>12</span><br><br><span>=240</span><span>÷</span><span>12</span><br><br><span>=20（天）</span><br><br><span>答：剩下的还要看20天．</span><br><br><span>【点评】</span><span>本题考查了简单的三步计算的整数乘除应用题的能力．关键是求出剩下的页数．</span><br><br><span>20．（5分）王军的张数是李明张数的3倍，如果王军拿60张邮票送给李明，两人的邮票张数一样多，王军有邮票多少张？（列方程解）</span><br><br><span>【分析】</span><span>由题意可知：王军的张数﹣60=李军的张数</span><span>+</span><span>60，据此等量关系式，即可列方程求解．</span><br><br><span>【解答】</span><span>解：设李明有x张，则王军有3x张，</span><br><br><span>3x﹣60=x</span><span>+</span><span>60</span><br><br><span> 2x=120</span><br><br><span> x=60</span><br><br><span>60</span><span>×</span><span>3=180（张）</span><br><br><span>答：王军有邮票180张．</span><br><br><span>【点评】</span><span>解答此题的关键是：弄清楚数量间的关系，得出等量关系式，问题即可得解．</span><br><br><span>21．（4分）一辆汽车从甲地开往乙地，前2小时行驶了136千米，照这样的速度行完全程需用12小时，甲乙两地相距多少千米？</span><br><br><span>【分析】</span><span>“照这样的速度”说明每小时行驶的路程相同，先用136千米除以2小时，求出每小时行驶的路程，再乘上行驶的总时间12小时，即可求出甲乙两地之间的距离．</span><br><br><span>【解答】</span><span>解：136</span><span>÷</span><span>2</span><span>×</span><span>12</span><br><br><span>=68</span><span>×</span><span>12</span><br><br><span>=816（千米）</span><br><br><span>答：甲乙两地相距816千米．</span><br><br><span>【点评】</span><span>解决本题先根据速度=路程</span><span>÷</span><span>时间，求出不变的速度，再根据路程=速度</span><span>×</span><span>时间求解．</span><br><br><strong><span>七．计算题（共2小题，满分3分）</span></strong><br><br><span>22．（1分）简便计算．</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2018/1228/20181228155755.png?m=0.8600186083001202"><br><br><span>【分析】</span><span>（1）根据加法交换律和结合律进行简算；</span><br><br><span>（2）根据减法的性质进行简算；</span><br><br><span>（3）、（5）根据乘法分配律进行简算；</span><br><br><span>（4）根据除法的性质进行简算；</span><br><br><span>（6）根据乘法交换律和结合律进行简算．</span><br><br><span>【解答】</span><span>解：（1）372</span><span>+</span><span>535</span><span>+</span><span>128</span><span>+</span><span>265</span><br><br><span>=（372</span><span>+</span><span>128）</span><span>+</span><span>（535</span><span>+</span><span>265）</span><br><br><span>=500</span><span>+</span><span>800</span><br><br><span>=1300；</span><br><br><span>（2）600﹣259﹣141</span><br><br><span>=600﹣（259</span><span>+</span><span>141）</span><br><br><span>=600﹣400</span><br><br><span>=200；</span><br><br><span>（3）101</span><span>×</span><span>99</span><br><br><span>=（100</span><span>+</span><span>1）</span><span>×</span><span>99</span><br><br><span>=100</span><span>×</span><span>99</span><span>+</span><span>1</span><span>×</span><span>99</span><br><br><span>=9900</span><span>+</span><span>99</span><br><br><span>=9999；</span><br><br><span>（4）300</span><span>÷</span><span>25</span><span>÷</span><span>4</span><br><br><span>=300</span><span>÷</span><span>（25</span><span>×</span><span>4）</span><br><br><span>=300</span><span>÷</span><span>100</span><br><br><span>=3；</span><br><br><span>（5）32</span><span>×</span><span>56</span><span>+</span><span>32</span><span>×</span><span>43</span><span>+</span><span>32</span><br><br><span>=32</span><span>×</span><span>（56</span><span>+</span><span>43</span><span>+</span><span>1）</span><br><br><span>=32</span><span>×</span><span>100</span><br><br><span>=3200；</span><br><br><span>（6）125</span><span>×</span><span>6</span><span>×</span><span>5</span><span>×</span><span>8</span><br><br><span>=（125</span><span>×</span><span>8）</span><span>×</span><span>（6</span><span>×</span><span>5）</span><br><br><span>=1000</span><span>×</span><span>30</span><br><br><span>=30000．</span><br><br><span>【点评】</span><span>考查了运算定律与简便运算，四则混合运算．注意运算顺序和运算法则，灵活运用所学的运算定律简便计算．</span><br><br><span>23．（2分）参加运动会的女运动员有120人，比男运动员的2倍少6人．参加运动会的男运动员有多少人？</span><br><br><span>【分析】</span><span>根据题干，女运动员有120人，比男运动员的2倍少6人，那么男运动员的人数</span><span>×</span><span>2﹣6人=女运动员的人数，由此设男运动员有x人，列式解答即可．</span><br><br><span>【解答】</span><span>解：设男运动员有x人，</span><br><br><span>2x﹣6=120</span><br><br><span> 2x=126</span><br><br><span> x=126</span><span>÷</span><span>2</span><br><br><span> x=63</span><br><br><span>答：参加运动会的男运动员有63人．</span><br><br><span>【点评】</span><span>解答此题容易找出基本数量关系：男运动员的人数</span><span>×</span><span>2﹣6人=女运动员的人数．</span><br></div><div><span><br></span></div>
四年级上