2019年小升初数学《差倍问题》专项训练题及答案

<strong><span>应用题</span></strong><strong><span>&nbsp;</span></strong><br><br><span>1.王红家养了一些鸡,黄鸡比黑鸡多13只,白鸡比黄鸡多12只.白鸡的只数正好是黑鸡的2倍.白鸡、黄鸡、黑鸡各有多少只? &nbsp;&nbsp;&nbsp;</span><br><br><span>2.爸爸今年的年龄正好是小红的4倍,爸爸比小红大30岁,爸爸和小红今年分别是多少岁? &nbsp;&nbsp;&nbsp;</span><br><br><span>3.想一想,算一算. &nbsp;</span><br><br><span>(1)买一瓶墨水和一个文具盒应付多少钱? &nbsp;&nbsp;&nbsp;</span><br><br><span>(2)买一本童话书和一瓶墨水应付多少钱? &nbsp;&nbsp;&nbsp;</span><br><br><span>(3)买一支铅笔和一个文具盒应付多少钱? &nbsp;&nbsp;&nbsp;</span><br><br><span>(4)小明用10元钱去买一个文具盒,应找回多少钱? &nbsp;&nbsp;&nbsp;</span><br><br><span>4.小明在一次数学练习中得了75分,已知共有25道题,每做对一道题得4分,做错一道或不做扣1分。那么小明做对了多少道题? &nbsp;&nbsp;&nbsp;</span><br><br><span>&nbsp;<img src="https://www.szxuexiao.com/uploadimages/2019/0518/2019518233034.png?m=0.14625191487052325"></span><br><br><span>5.两个数的和是11.63,小强由于粗心,在计算时将一个加数的小数点向左移动了一位,结果得5.87,原来两个加数各是多少? &nbsp;&nbsp;&nbsp;</span><br><br><span>6.玻璃瓶里装着一些饮料,把饮料增加到原来的2倍,称得重5千克;把饮料增加到原来的4倍,称得重9千克,问原来瓶里的饮料重多少千克?瓶重多少千克? &nbsp;&nbsp;&nbsp;</span><br><br><span>7.星期天兄弟去钓鱼,如果哥哥比弟弟多钓26条,哥哥钓的鱼是弟弟的3 倍,求哥哥、弟弟各钓了多少条? &nbsp;&nbsp;&nbsp;</span><br><br><span>8.新光小学的人数比宏扬中学少1260人,已知宏扬中学的人数是新光小学的2.5倍.宏扬中学和新光小学各有多少人? &nbsp;&nbsp;&nbsp;</span><br><br><span>9.五年级学生捐款比六年级少150元,六年级捐款是五年级的1.6倍.五、六年级各捐多少? &nbsp;&nbsp;&nbsp;</span><br><br><span>10.嘟嘟和泡泡各有一些玻璃球,嘟嘟说:“你的玻璃球的个数比我少 1/4</span><span>。”泡泡说:“你要是给我你的1/6&nbsp;</span><span>,我就比你多2个了。”嘟嘟原来有多少个玻璃球?&nbsp;</span><div><br><span>11.甲书架上有32本书,乙书架上有57本书,甲每天增加4本书,乙每天增加9本书,多少天后乙是甲的两倍? &nbsp;&nbsp;&nbsp;</span><br><br><span>12.赵明有一份资料要复印25份.根据左边的价格表,算一算赵明选哪种印法更省钱?</span><div><br></div><div><img src="https://www.szxuexiao.com/uploadimages/2019/0518/2019518225047.png"><br><br><span>13.一只野兔每秒跑15.5米,一只小鹿每小时跑90千米,小鹿和野兔谁跑得快?&nbsp;</span></div><div><br><span>14.看图计算. &nbsp;</span><br><br><span>&nbsp;<img src="https://www.szxuexiao.com/uploadimages/2019/0518/2019518233223.png?m=0.3407877783122557"></span><br><br><span>15.下图中哪个苹果是正确的?</span><span><br></span><br><img src="https://www.szxuexiao.com/uploadimages/2019/0518/201951823335.png?m=0.8292007655917621"><br><br><span>16.某工厂为支援地震灾区赶制一批帐篷,第一天生产了总帐篷数的20%,第二天生产了总帐篷数的 7/20</span><span>,两天共生产帐篷4400顶。这批帐篷一共有多少顶?&nbsp;</span></div><div><br><span>17.兄弟俩共养鸡1000只,哥哥养的鸡的 1/3</span><span>比弟弟养的鸡的1/10&nbsp;</span><span>多160只,问哥哥和弟弟各养鸡多少只? &nbsp;&nbsp;&nbsp;</span><br><br><span>18.两个数的和是11.63,小强由于粗心,在计算时将一个加数的小数点向左移动了一位,结果和是5.87,原来的两个加数各是多少? &nbsp;&nbsp;&nbsp;</span><br><br><br><div style="text-align: center;"><font color="#38761d"><strong>2019年小升初数学《差倍问题》专项训练题参考</strong><strong>答案</strong><strong>&nbsp;</strong></font></div><br><span><strong>应用题</strong></span><br><br><span>1.解:黑鸡:(13+12)÷(2﹣1)</span><span><br></span><span><br></span></div><div><span>=25÷1</span><span><br></span><span><br></span></div><div><span>=25(只)</span><span><br></span><span><br></span></div><div><span>白鸡:25×2=50(只)</span><span><br></span><span><br></span></div><div><span>黄鸡:25+13=38(只)</span><span><br></span><span><br></span></div><div><span>答:白鸡有50只,黄鸡有38只,黑鸡有25只. &nbsp;</span><br><br><span>2.解:小红的年龄:30÷(4﹣1)</span><span><br></span><span><br></span></div><div><span>=30÷3</span><span><br></span><span><br></span></div><div><span>=10(岁),</span><span><br></span><span><br></span></div><div><span>爸爸的年龄:30+10=40(岁),</span><span><br></span><span><br></span></div><div><span>答:爸爸40岁,小红10岁. &nbsp;</span><br><br><span>3.(1)解:2+8=10(元)</span><span><br></span><span><br></span></div><div><span>(2)解:18+2=20(元)</span><span><br></span><span><br></span></div><div><span>(3)解:8+1=9(元)</span><span><br></span><span><br></span></div><div><span>(4)解:10-8=2(元) &nbsp;</span><br><br><span>4.解:(25×4-75)÷(4+1)=5(道)25-5=20(道)</span><span><br></span><span><br></span></div><div><span>答:小明做对了20道题。 &nbsp;</span><br><br><span>5.解:(11.63-5.87)÷(10-1)</span><span><br></span><span><br></span></div><div><span>=5.76÷9</span><span><br></span><span><br></span></div><div><span>=0.64</span><span><br></span><span><br></span></div><div><span>所以一个加数是0.64×10=6.4,</span><span><br></span><span><br></span></div><div><span>另一个加数是:11.63-6.4=5.23</span><br><br><span>答:原来两个加数分别是6.4、5.23。</span><br><br><span>6.解:饮料的2倍是:9﹣5=4(千克),</span><span><br></span><span><br></span></div><div><span>所以原来饮料重:4÷2=2(千克);</span><span><br></span><span><br></span></div><div><span>瓶子重:5﹣2×2,</span><span><br></span><span><br></span></div><div><span>=5﹣4,</span><span><br></span><span><br></span></div><div><span>=1(千克),</span><span><br></span><span><br></span></div><div><span>答:原来瓶内的饮料重2千克,瓶子重1千克 &nbsp;</span><br><br><span>7.解:26÷(3-1)=13(条)&nbsp;&nbsp; 13×3=39(条)答:弟弟钓13条,哥哥钓39条。 &nbsp;</span><br><br><span>8.【分析】由题意可知:宏扬中学的人数=新光小学的人数×2.5,设新光小学的人数为x人,则宏扬中学的人数为2.5x人,再据新光小学的人数比宏扬中学少1260人,即可列方程求解. &nbsp;</span><br><br><span>9.解:150÷(1.6﹣1)</span><span><br></span><span><br></span></div><div><span>=150÷0.6</span><span><br></span><span><br></span></div><div><span>=250(元)</span><span><br></span><span><br></span></div><div><span>250×1.6=400(元)</span><span><br></span><span><br></span></div><div><span>答:五年级学生捐款250元,六年级学生捐款400元. &nbsp;</span><br><br><span>10.2÷(1/6</span><span>×2-1/4</span><span>)=2÷(1/3</span><span>-1/4</span><span>)=2÷1/12</span><span>=24(个).</span><span><br></span><span><br></span></div><div><span>答:都都原有玻璃球24个. &nbsp;</span><br><br><span>11.解:设x天后,乙书架书是甲书架的2倍</span><span><br></span><span><br></span></div><div><span>57+9x=2(32+4x)</span><span><br></span><span><br></span></div><div><span>57+9x=64+8x</span><span><br></span><span><br></span></div><div><span>&nbsp;&nbsp;&nbsp; x=64﹣57</span><span><br></span><span><br></span></div><div><span>&nbsp;&nbsp;&nbsp; x=7</span><span><br></span><span><br></span></div><div><span>答:7天后,乙书架书是甲书架的2倍. &nbsp;</span><br><br><span>12.解:复印:0.40×25=10(元);</span><span><br></span><span><br></span></div><div><span>速印:0.20×30+2.00=8(元);</span><span><br></span><span><br></span></div><div><span>10>8,即速印省钱</span><span><br></span><span><br></span></div><div><span>答:速印法更省钱。 &nbsp;</span><br><br><span>13.小鹿跑得快。 &nbsp;</span><br><br><span>14.12只 &nbsp;</span><br><br><span>15.答:第二个与第四个苹果是正确的。 &nbsp;</span><br><br><span>16.解:两天的生产量是总帐篷数的(20%+7/20&nbsp;</span><span>)</span><span><br></span><span><br></span></div><div><span>这批帐篷的总数:4400÷(20%+</span>7/20)=8000(顶)</div><div><span></span><span><br></span></div><div><span>答:这批帐篷一共有多少8000顶 &nbsp;</span><br><br><span>17. 解:设弟弟养鸡了x只,则哥哥就养了1000﹣x只, &nbsp;</span><br><br><img src="https://www.szxuexiao.com/uploadimages/2019/0518/2019518233741.png?m=0.19811208072761022"><br><br><span>答:哥哥养鸡600只,弟弟养鸡400只</span><br><br><span>18.解:﹙11.63-5.87﹚÷﹙10-1﹚=0.64; 0.64×10=6.4 ;11.63-6.4=5.23&nbsp;&nbsp;</span><br></div></div>