【2022-7-11】数学天天练（1-6年级）
<h1 style="color: black; text-align: left; margin-bottom: 10px;"><span style="color: black;"><img src="https://mmbiz.qpic.cn/mmbiz_jpg/R7UlJAeRNw0ccDeId3WlNW6H2P6os1y39TZR5YiaDxVbnib6BRkv3WmBO8vM4nZTHPUJYzsjzwxQDOgHFfZk53Aw/640?wx_fmt=jpeg&tp=webp&wxfrom=5&wx_lazy=1&wx_co=1" style="width: 50%; margin-bottom: 20px;"></span><span style="color: black;"><strong style="color: blue;">中小学学习群</strong></span><span style="color: black;">和100万个家庭<span style="color: black;">一块</span>成长</span><a style="color: black;"><span style="color: black;">进群</span></a></h1>
<h1 style="color: black; text-align: left; margin-bottom: 10px;"><span style="color: black;">1-6年级数学口算训练（附答案），可下载打印！</span></h1>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;"><strong style="color: blue;"><span style="color: black;">进群</span></strong><span style="color: black;">，每日<span style="color: black;">18:00</span></span></span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">保持</span>-</strong><span style="color: black;">数学天天练</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"><strong style="color: blue;">奥数拔高</strong></span><span style="color: black;"><strong style="color: blue;">（选做）</strong></span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">一年级</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 三年级（1）班有28个女生，有34个男生，男生比女生多多少个人？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 文具店有45支铅笔，上午卖38支，下午新进了27支，还有多少支铅笔？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 计算</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">67-57+39 85-23-16 75+12-25</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">二年级</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 计算</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">363+188＝ 587＋126＝ 501-167＝</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">671-188＝ 601-265＝ 177+246＝</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 小香的奶奶养的灰兔子有9只，白兔子是灰兔子的5倍。小香的奶奶一共养了多少只兔子？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 小花买了3筒羽毛球，每筒9元。小雨给了售货员50元钱，应该找回多少元？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">三年级</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 比5.4少0.8是（ ）；比5.4米多1.8米是（ ）米。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 一本《童话故事》13.9元，一本《历史回顾》16.7元，买一本《童话故事》和一本《历史回顾》共需要多少元？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 小红用了27元钱买了3本练习册。小青买12本<span style="color: black;">这般</span>的练习本，需要花多少元？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">4. 列竖式计算下面各题。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">320÷2= 560÷4= 870÷3=</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">四年级</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1.计算</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">16.47-8.55+3.18 9.5+4.85-6.36 </span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">12.8+4.15+6.85</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. <span style="color: black;">朋友</span>们排成一列做操，军军从前面数排在第12位，从后面数排在第18位，这一列一共有多少人？</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 有<span style="color: black;">有些</span>长短相同的木棒粘接在<span style="color: black;">一块</span>，粘接好后如下图，这3根木棒粘接在<span style="color: black;">一块</span>长（ ）。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"><img src="https://mmbiz.qpic.cn/mmbiz_png/MmY82WtDhxo5KOOPOIljl0K7DuOJOKXdAdzupA2E66o37lR7ZP7wK45wRibibMzQfSlV8MibMCdT0bicsanmHiafqzg/640?wx_fmt=png&random=0.34342743055318303&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;"></span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">五年级</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 把下面的分数化成小数。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"><img src="https://mmbiz.qpic.cn/mmbiz_png/MmY82WtDhxo5KOOPOIljl0K7DuOJOKXd7By90wm3NFAvgm3QsXSYtgSTsfUkt1A7oS1hArF1fLypeXg0MmIZ3Q/640?wx_fmt=png&random=0.7006485541253162&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;"></span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 一个长方体水箱,底面长15分米,宽8分米。<span style="color: black;">倘若</span>要向这个水箱注入3分米深的水,需要多少升水?</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 李阿姨家的粮油店里有一种长方体油桶，底面积是24平方分米，最多<span style="color: black;">能够</span>装57.6千克油，<span style="color: black;">倘若</span>每升油重0.8千克，油桶的高是多少分米？（材料厚度忽略不计）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">六年级</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 一铁路隧道长2000米，一列火车从车头进入隧道到车尾离开隧道用了一分钟，整列火车完全在隧道内的时间是40秒．求火车的车长及其行驶的速度．</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 一只手表每小时慢5分钟，照<span style="color: black;">这般</span>计算，早上6时对准标准时间后，当手表指示下午5时整时，标准时间是多少？</span></p><img src="https://mmbiz.qpic.cn/mmbiz_gif/7QRTvkK2qC6Lpa4AERic08bFeJp1x3QySwA4HIMI61IdSOgQvw1ZOI4PVgrnocETCnziaSpO48KFSSNicVhqe9fDw/640?wx_fmt=gif&random=0.44266254729393006&wxfrom=5&wx_lazy=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">参考答案</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">一年级</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 34-28=6（个）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：男生比女生多6个人。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 45-38+27=34（支）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：还有34支铅笔。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 49 46 62</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">二年级</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 551 713 334</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"> 483 336 423</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 5×9+9=54（只）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：一共养了54只兔子。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 50-3×9=23（元）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：该找回23元。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">三年级</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 4.6；7.2</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 13.9＋16.7＝30.6（元）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：买一本《童话故事》和一本《历史回顾》共需要30.6元。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 27÷3×12＝108（元）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：需要108元。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">4. 160 140 290</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">四年级</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 11.1 7.89 23.8</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 12＋18－1＝29（人）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：这一列一共有29人。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 5×2＝10（毫米），10毫米＝1厘米</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">5－1＝4（厘米）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">5×2＋4＝14（厘米）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">五年级</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 0.04 0.133 0.556 0.125 </span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">0.22 1.35 0.35 0.004</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2. 15×8×3=360(立方分米)</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">360立方分米=360升</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：需要360升水。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">3. 57.6÷0.8÷24=3（分米）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：油桶的高是3分米。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><strong style="color: blue;"><span style="color: black;">六年级</span></strong></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">1. 解：设火车的长度为x米，<span style="color: black;">按照</span>题意得：</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"><img src="https://mmbiz.qpic.cn/mmbiz_png/MmY82WtDhxo5KOOPOIljl0K7DuOJOKXdyGHVfK2JqCbkliby1aAUlRyknUuYcKzYaomEhwnk8XJBGUfVHhWvKmw/640?wx_fmt=png&random=0.5344751229801865&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;"></span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">x＝400</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">（2000﹣400）÷40＝40（米/秒）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：车长400米，行驶速度40米/秒．</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">2. 5+12=17时，</p>设标准时间经过了x小时，则
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">（6+x-17）×60-5x=0，</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"> x=12</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">6：00+12=18：00</p><span style="color: black;">因此</span>准确时间应该是18：00．
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"><strong style="color: blue;"><span style="color: black;"><strong style="color: blue;">奥数拔高</strong></span><span style="color: black;"><strong style="color: blue;">（选做）</strong></span></strong></span></p><img src="https://mmbiz.qpic.cn/mmbiz_gif/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqiaTK7c5IBBdqtGqicTcfBb9LDtwvuyjYm9qXVeIrNnkIBkWvuyVhWnFg/640?wx_fmt=gif&wxfrom=5&wx_lazy=1&tp=webp" style="width: 50%; margin-bottom: 20px;">一年级<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqQGJ9ksR1liaCakn8ecl1ibBhls6feJxDllVRl2YoiapEyI3JUs6ynuribg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">时钟6点钟敲6下，用了10秒，12点敲12下，用多<span style="color: black;">长期</span>？</span></p><img src="https://mmbiz.qpic.cn/mmbiz_gif/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqiaTK7c5IBBdqtGqicTcfBb9LDtwvuyjYm9qXVeIrNnkIBkWvuyVhWnFg/640?wx_fmt=gif&wxfrom=5&wx_lazy=1&tp=webp" style="width: 50%; margin-bottom: 20px;">二年级<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqQGJ9ksR1liaCakn8ecl1ibBhls6feJxDllVRl2YoiapEyI3JUs6ynuribg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;"> 小梅从1楼<span style="color: black;">步行到</span>4楼需要3分钟，<span style="color: black;">那样</span>用<span style="color: black;">一样</span>的速度，他从1楼<span style="color: black;">步行到</span>7楼需要多少分钟？</span></p><img src="https://mmbiz.qpic.cn/mmbiz_gif/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqiaTK7c5IBBdqtGqicTcfBb9LDtwvuyjYm9qXVeIrNnkIBkWvuyVhWnFg/640?wx_fmt=gif&wxfrom=5&wx_lazy=1&tp=webp" style="width: 50%; margin-bottom: 20px;">三年级<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqQGJ9ksR1liaCakn8ecl1ibBhls6feJxDllVRl2YoiapEyI3JUs6ynuribg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">一只蜘蛛在一个长方体木块的顶点G处，已知这个长方体木块的长是80厘米，宽40厘米，高80厘米，<span style="color: black;">需求</span>蜘蛛在爬行过程中只能前进，<span style="color: black;">不可</span>后退，只能在棱上爬，且同一条棱<span style="color: black;">不可</span>爬两次．<span style="color: black;">那样</span>这只蜘蛛最多<span style="color: black;">能够</span>爬行（）厘米．</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3Fa4RNp25lO1tHsGquEyIsPTeBbuVtwCCVWdWKicwDcPNezH0xKFTZsG3bQ2SkIeZkA00cZEQkV9c7A/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;"></p><img src="https://mmbiz.qpic.cn/mmbiz_gif/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqiaTK7c5IBBdqtGqicTcfBb9LDtwvuyjYm9qXVeIrNnkIBkWvuyVhWnFg/640?wx_fmt=gif&wxfrom=5&wx_lazy=1&tp=webp" style="width: 50%; margin-bottom: 20px;">四年级<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqQGJ9ksR1liaCakn8ecl1ibBhls6feJxDllVRl2YoiapEyI3JUs6ynuribg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">2010个自然数由小到大排成一排，排在奇数位上的各数的平均数是2345，<span style="color: black;">那样</span>偶数位上各数的平均数是多少？</span></p><img src="https://mmbiz.qpic.cn/mmbiz_gif/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqiaTK7c5IBBdqtGqicTcfBb9LDtwvuyjYm9qXVeIrNnkIBkWvuyVhWnFg/640?wx_fmt=gif&wxfrom=5&wx_lazy=1&tp=webp" style="width: 50%; margin-bottom: 20px;">五年级<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqQGJ9ksR1liaCakn8ecl1ibBhls6feJxDllVRl2YoiapEyI3JUs6ynuribg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">一项工程，甲、乙、丙三人合作需要13天，<span style="color: black;">倘若</span>丙<span style="color: black;">休憩</span>2天，乙要多做4天，<span style="color: black;">或</span>由甲、乙合作多做1天。问：这项工程由甲单独做需要多少天？</p>
<img src="https://mmbiz.qpic.cn/mmbiz_gif/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqiaTK7c5IBBdqtGqicTcfBb9LDtwvuyjYm9qXVeIrNnkIBkWvuyVhWnFg/640?wx_fmt=gif&tp=webp&wxfrom=5&wx_lazy=1" style="width: 50%; margin-bottom: 20px;">六年级<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqQGJ9ksR1liaCakn8ecl1ibBhls6feJxDllVRl2YoiapEyI3JUs6ynuribg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">学校举办语文、数学双科竞赛，三年级一班有59人，参加语文竞赛的有36人，参加数学竞赛的有38人，一科<span style="color: black;">亦</span>没参加的有5人。双科都参加的有多少人？</span></p><img src="https://mmbiz.qpic.cn/mmbiz_jpg/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqibmgOSsia2IgOmTEtspx7WB1Nhria1WkT3tcaHs6csrHg3e8A30NQcyOw/640?wx_fmt=jpeg&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答案</span></p><img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqTJmBsPp0ny6icdtCYtxChBIS9vh5B1S7t50PlVSYEAdV2JMoRCAziaicg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">一年级<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">【答案】 22秒</span><span style="color: black;">【解析】 时钟敲6下，中间有6-1=5(个)间隔，一共用了10秒，<span style="color: black;">由于</span>2+2+2+2+2=10，<span style="color: black;">因此</span><span style="color: black;">每一个</span>间隔2秒．12点敲12下，中间有12-1=11(个)间隔，即11个2相加，2+2+2+2+2+2+2+2+2+2+2=22(秒)．</span></p><img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqTJmBsPp0ny6icdtCYtxChBIS9vh5B1S7t50PlVSYEAdV2JMoRCAziaicg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">二年级<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答案：小明从1楼<span style="color: black;">步行到</span>4楼，<span style="color: black;">实质</span>只走了三个间隔的台阶，走三个间隔的台阶需要3分钟，<span style="color: black;">那样</span>走一个间隔的台阶需要1分钟．<span style="color: black;">此刻</span>他从1楼<span style="color: black;">步行到</span>7楼要走6个间隔的台阶，一共需要6分钟。</span></p><img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqTJmBsPp0ny6icdtCYtxChBIS9vh5B1S7t50PlVSYEAdV2JMoRCAziaicg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">三年级<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">【答案】 680</p>【解析】 图中八个顶点均为奇点，<span style="color: black;">因此</span><span style="color: black;">不可</span>一笔画，要使其能一笔画，<span style="color: black;">最少</span>要去掉三条棱，使图中<span style="color: black;">仅有</span>两个奇点，就<span style="color: black;">能够</span>满足一笔画的<span style="color: black;">要求</span>．长方体的棱长总和<span style="color: black;">必定</span>，(80+80+40)×4=800(厘米)，<span style="color: black;">因此呢</span>去掉的三条棱越短，蜘蛛爬过的距离就越远．<span style="color: black;">因此</span><span style="color: black;">咱们</span>去掉三条棱长为40厘米的棱，于是可知，
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">蜘蛛爬行的最远距离为：800-40×3=680(厘米)。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">蜘蛛的爬行路径为：G→F→C→D→G→H→A→B→E→H(如图)。</p><span style="color: black;">重视</span>：这是一个立体图形，它有八个顶点，<span style="color: black;">咱们</span>把长方体的棱看作顶点与顶点之间的连线，蜘蛛只能前进<span style="color: black;">不可</span>后退，并且每一条棱<span style="color: black;">不可</span>爬两次。
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3Fa4RNp25lO1tHsGquEyIsPTCKqSic5aubwIz6AczrTjMMDlj5Oy2cjtWnl9xTwr3X3satMbe78X8XA/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;"></p><img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqTJmBsPp0ny6icdtCYtxChBIS9vh5B1S7t50PlVSYEAdV2JMoRCAziaicg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">四年级<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">答案：2346</p>解析：有2010个数字，<span style="color: black;">那样</span>奇数就有1005个，偶数<span style="color: black;">亦</span>是1005个。<span style="color: black;">因为</span>奇数平均数<span style="color: black;">便是</span>中间的数字，<span style="color: black;">因此</span>奇数中间数是2345，<span style="color: black;">那样</span>偶数位上的数是2346.
<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqTJmBsPp0ny6icdtCYtxChBIS9vh5B1S7t50PlVSYEAdV2JMoRCAziaicg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">五年级<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">解：丙做2天，乙要做4天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">亦</span><span style="color: black;">便是</span>说并做1天乙要做2天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">那样</span>丙13天的工作量乙要2×13=26天完成</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">乙做4天相当于甲乙合作1天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">亦</span><span style="color: black;">便是</span>乙做3天等于甲做1天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">设甲单独完成需要a天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">那样</span>乙单独做需要3a天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">丙单独做需要3a/2天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">按照</span>题意</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">1/a+1/3a+1/（3a/2）=1/13</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">1/a(1+1/3+2/3）=1/13</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">1/a×2=1/13</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">a=26</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">甲单独做需要26天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">算术法：丙做13天相当于乙做26天</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">乙做13+26=39天相当于甲做39/3=13天</p><span style="color: black;">因此</span>甲单独完成需要13+13=26天
<img src="https://mmbiz.qpic.cn/mmbiz_png/iaYPkKHKB3FbDBmkan5apRsj5d7XwsqpqTJmBsPp0ny6icdtCYtxChBIS9vh5B1S7t50PlVSYEAdV2JMoRCAziaicg/640?wx_fmt=png&wxfrom=5&wx_lazy=1&wx_co=1&tp=webp" style="width: 50%; margin-bottom: 20px;">六年级<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">分析：参加语文竞赛的36人中有参加数学竞赛的，<span style="color: black;">一样</span>参加数学竞赛的38人中<span style="color: black;">亦</span>有参加语 文竞赛的，<span style="color: black;">倘若</span>把两者加起来，<span style="color: black;">那样</span>既参加语文竞赛又参加数学竞赛的人数就统计了两次，<span style="color: black;">因此</span>将参加语文竞赛的人数加上参加数学竞赛的人数再加上一科<span style="color: black;">亦</span>没参加 的人数减去全班人数<span style="color: black;">便是</span>双科都参加的人数。</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">解：36+38+5-59=20（人）</span></p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">答：双科都参加的有20人。</span></p><strong style="color: blue;"><img src="https://mmbiz.qpic.cn/mmbiz_gif/V71TZateWmO51ic6AMVhX8Lf6RjyLzQk9fSo4Vu2E7NVGzr3xB7Z9wQfEWRHjTwRtdgMo8lnhryqkRHkLnEw4xg/640?wx_fmt=gif&tp=webp&wxfrom=5&wx_lazy=1" style="width: 50%; margin-bottom: 20px;"></strong><strong style="color: blue;"><span style="color: black;"><strong style="color: blue;"><strong style="color: blue;">其余资料请点击</strong></strong></span></strong><span style="color: black;"><strong style="color: blue;"><span style="color: black;"><strong style="color: blue;"><strong style="color: blue;">阅读原文</strong></strong></span></strong></span>
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