Bài 26: Đơn Vị Đo Độ Dài
<h3 id="khaacutem-phaacute">Khám phá</h3> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/321-1662094223.png.webp" width="720" height="210" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-0" title="hinh-anh-bai-26-don-vi-do-do-dai-333-0" loading="lazy"></p><div> <div class="ads-horizontal-wrapped" style="height: auto !important; min-height: 0px !important;">
<span class="ads-title">Advertisement</span>
<script async="" src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-8123786206223951" crossorigin="anonymous" type="text/javascript" data-checked-head="true"></script>

<ins class="adsbygoogle" style="display: block; height: 280px;" data-ad-client="ca-pub-8123786206223951" data-ad-slot="2203391893" data-ad-format="auto" data-full-width-responsive="true" data-adsbygoogle-status="done" data-ad-status="unfilled"><div id="aswift_1_host" style="border: none; height: 280px; width: 741px; margin: 0px; padding: 0px; position: relative; visibility: visible; background-color: transparent; display: inline-block; overflow: visible;" tabindex="0" title="Advertisement" aria-label="Advertisement"><iframe id="aswift_1" name="aswift_1" style="left:0;position:absolute;top:0;border:0;width:741px;height:280px;" sandbox="allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation" width="741" height="280" frameborder="0" marginwidth="0" marginheight="0" vspace="0" hspace="0" allowtransparency="true" scrolling="no" src="https://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-8123786206223951&amp;output=html&amp;h=280&amp;slotname=2203391893&amp;adk=3553368404&amp;adf=2501886532&amp;pi=t.ma~as.2203391893&amp;w=741&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1690924519&amp;rafmt=1&amp;format=741x280&amp;url=https%3A%2F%2Fsachgiaokhoa.online%2Fbai-26-don-vi-do-do-dai-333G2942.html&amp;fwr=0&amp;fwrattr=true&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;uach=WyJtYWNPUyIsIjEzLjAuMCIsIng4NiIsIiIsIjExNS4wLjU3OTAuMTE0IixbXSwwLG51bGwsIjY0IixbWyJOb3QvQSlCcmFuZCIsIjk5LjAuMC4wIl0sWyJHb29nbGUgQ2hyb21lIiwiMTE1LjAuNTc5MC4xMTQiXSxbIkNocm9taXVtIiwiMTE1LjAuNTc5MC4xMTQiXV0sMF0.&amp;dt=1690924519355&amp;bpp=2&amp;bdt=522&amp;idt=180&amp;shv=r20230731&amp;mjsv=m202307270501&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D94547395a8fa18af-22e89ad22ae300c0%3AT%3D1690912062%3ART%3D1690924219%3AS%3DALNI_MYNbCG599XmevrUPCYJ3Zv-Np5EvA&amp;gpic=UID%3D00000d3b2ce8a729%3AT%3D1690912062%3ART%3D1690924219%3AS%3DALNI_MaVlHrwAJeI0KGbMoTcFZDk5BwO2Q&amp;prev_fmts=0x0&amp;nras=1&amp;correlator=4554851404379&amp;frm=20&amp;pv=1&amp;ga_vid=54020647.1690924519&amp;ga_sid=1690924519&amp;ga_hid=809959674&amp;ga_fc=0&amp;u_tz=420&amp;u_his=50&amp;u_h=1080&amp;u_w=1920&amp;u_ah=1055&amp;u_aw=1920&amp;u_cd=24&amp;u_sd=1&amp;dmc=8&amp;adx=394&amp;ady=809&amp;biw=1910&amp;bih=970&amp;scr_x=0&amp;scr_y=0&amp;eid=44759842%2C44759875%2C44759926%2C31076484%2C42531706%2C44788441%2C44792013&amp;oid=2&amp;pvsid=3956206253602818&amp;tmod=2137688851&amp;uas=0&amp;nvt=1&amp;fc=1920&amp;brdim=0%2C25%2C0%2C25%2C1920%2C25%2C1920%2C1055%2C1920%2C970&amp;vis=1&amp;rsz=%7C%7CoeE%7C&amp;abl=CS&amp;pfx=0&amp;fu=128&amp;bc=31&amp;ifi=2&amp;uci=a!2&amp;fsb=1&amp;xpc=9uqNZA4Qtu&amp;p=https%3A//sachgiaokhoa.online&amp;dtd=193" data-google-container-id="a!2" data-google-query-id="CJbS2tqwvIADFZPElgodKw8KUg" data-load-complete="true"></iframe></div></ins>
<script type="text/javascript">
            (adsbygoogle = window.adsbygoogle || []).push({});
        </script>
</div>
</div>a)<img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/322-1662094233.png.webp" width="700" height="288" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-1" title="hinh-anh-bai-26-don-vi-do-do-dai-333-1" loading="lazy"><p></p> <p>b)<img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/323-1662094242.png.webp" width="564" height="202" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-2" title="hinh-anh-bai-26-don-vi-do-do-dai-333-2" loading="lazy"></p> <p>Trong hình trên, đồ vật nào dài nhất?</p> <h3 id="hoat-dong">Hoạt động</h3> <p><strong>Khám phá lớp học</strong></p> <p>Em hãy ước lượng độ dài các đồ vật trong lớp học bằng gang tay.</p> <p>Đo độ dài thực tế của chúng bằng gang tay.</p> <table style="border-collapse: collapse; width: 99.9265%; height: auto !important;" border="1"> <tbody> <tr> <td style="width: 30.2382%; text-align: center;"><strong>Đồ vật</strong></td> <td style="width: 30.2382%; text-align: center;"><strong>Ước lượng</strong></td> <td style="width: 30.2428%; text-align: center;"><strong>Thực tế</strong></td> </tr> <tr> <td style="width: 30.2382%;"><img src="/uploads/tinymce/331-1662094343.png.webp" width="169" height="184" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-3" title="hinh-anh-bai-26-don-vi-do-do-dai-333-3" loading="lazy"></td> <td style="width: 30.2382%;">... gang tay</td> <td style="width: 30.2428%;">... gang tay</td> </tr> <tr> <td style="width: 30.2382%;"><img src="/uploads/tinymce/332-1662094350.png.webp" width="202" height="172" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-4" title="hinh-anh-bai-26-don-vi-do-do-dai-333-4" loading="lazy"></td> <td style="width: 30.2382%;">... gang tay</td> <td style="width: 30.2428%;">... gang tay</td> </tr> <tr style="height: auto !important;"> <td style="width: 30.2382%; height: auto !important;"><img src="/uploads/tinymce/333-1662094356.png.webp" width="145" height="168" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-5" title="hinh-anh-bai-26-don-vi-do-do-dai-333-5" loading="lazy"><div> <div class="ads-horizontal-wrapped">
<span class="ads-title">Advertisement</span>
<script async="" src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-8123786206223951" crossorigin="anonymous" type="text/javascript" data-checked-head="true"></script>

<ins class="adsbygoogle" style="display: block; height: 0px;" data-ad-client="ca-pub-8123786206223951" data-ad-slot="2203391893" data-ad-format="auto" data-full-width-responsive="true" data-adsbygoogle-status="done" data-ad-status="unfilled"><div id="aswift_2_host" style="border: none; height: 0px; width: 225px; margin: 0px; padding: 0px; position: relative; visibility: visible; background-color: transparent; display: inline-block; overflow: visible; opacity: 1;" tabindex="0" title="Advertisement" aria-label="Advertisement"><iframe id="aswift_2" name="aswift_2" style="left: 0px; position: absolute; top: 0px; border: 0px; width: 225px; height: 0px;" sandbox="allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation" width="225" height="0" frameborder="0" marginwidth="0" marginheight="0" vspace="0" hspace="0" allowtransparency="true" scrolling="no" src="https://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-8123786206223951&amp;output=html&amp;h=600&amp;slotname=2203391893&amp;adk=3623281844&amp;adf=1041429250&amp;pi=t.ma~as.2203391893&amp;w=225&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1690924519&amp;rafmt=1&amp;format=225x600&amp;url=https%3A%2F%2Fsachgiaokhoa.online%2Fbai-26-don-vi-do-do-dai-333G2942.html&amp;fwr=0&amp;fwrattr=true&amp;rpe=1&amp;resp_fmts=4&amp;wgl=1&amp;uach=WyJtYWNPUyIsIjEzLjAuMCIsIng4NiIsIiIsIjExNS4wLjU3OTAuMTE0IixbXSwwLG51bGwsIjY0IixbWyJOb3QvQSlCcmFuZCIsIjk5LjAuMC4wIl0sWyJHb29nbGUgQ2hyb21lIiwiMTE1LjAuNTc5MC4xMTQiXSxbIkNocm9taXVtIiwiMTE1LjAuNTc5MC4xMTQiXV0sMF0.&amp;dt=1690924519357&amp;bpp=1&amp;bdt=524&amp;idt=237&amp;shv=r20230731&amp;mjsv=m202307270501&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D94547395a8fa18af-22e89ad22ae300c0%3AT%3D1690912062%3ART%3D1690924219%3AS%3DALNI_MYNbCG599XmevrUPCYJ3Zv-Np5EvA&amp;gpic=UID%3D00000d3b2ce8a729%3AT%3D1690912062%3ART%3D1690924219%3AS%3DALNI_MaVlHrwAJeI0KGbMoTcFZDk5BwO2Q&amp;prev_fmts=0x0%2C741x280&amp;nras=1&amp;correlator=4554851404379&amp;frm=20&amp;pv=1&amp;ga_vid=54020647.1690924519&amp;ga_sid=1690924519&amp;ga_hid=809959674&amp;ga_fc=0&amp;u_tz=420&amp;u_his=50&amp;u_h=1080&amp;u_w=1920&amp;u_ah=1055&amp;u_aw=1920&amp;u_cd=24&amp;u_sd=1&amp;dmc=8&amp;adx=406&amp;ady=2494&amp;biw=1910&amp;bih=970&amp;scr_x=0&amp;scr_y=0&amp;eid=44759842%2C44759875%2C44759926%2C31076484%2C42531706%2C44788441%2C44792013&amp;oid=2&amp;pvsid=3956206253602818&amp;tmod=2137688851&amp;uas=0&amp;nvt=1&amp;fc=1920&amp;brdim=0%2C25%2C0%2C25%2C1920%2C25%2C1920%2C1055%2C1920%2C970&amp;vis=1&amp;rsz=d%7C%7CoEebr%7Cp&amp;abl=XS&amp;pfx=0&amp;fu=128&amp;bc=31&amp;ifi=3&amp;uci=a!3&amp;btvi=1&amp;fsb=1&amp;xpc=8lBRUG4hWC&amp;p=https%3A//sachgiaokhoa.online&amp;dtd=243" data-google-container-id="a!3" data-google-query-id="CJby3dqwvIADFVvTFgUdL-MD8A" data-load-complete="true"></iframe></div></ins>
<script type="text/javascript">
            (adsbygoogle = window.adsbygoogle || []).push({});
        </script>
</div>
</div></td> <td style="width: 30.2382%;">... gang tay</td> <td style="width: 30.2428%;">... gang tay</td> </tr> <tr> <td style="width: 30.2382%;"><img src="/uploads/tinymce/334-1662094364.png.webp" width="231" height="160" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-6" title="hinh-anh-bai-26-don-vi-do-do-dai-333-6" loading="lazy"></td> <td style="width: 30.2382%;">... gang tay</td> <td style="width: 30.2428%;">... gang tay</td> </tr> </tbody> </table> <h3 id="khaacutem-phaacute">Khám phá</h3> <p><strong>Xăng-ti-mét</strong></p> <p>Thước có vạch kẻ chi thành từng xăng-ti-mét.</p> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/341-1662094402.png.webp" width="85" height="66" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-7" title="hinh-anh-bai-26-don-vi-do-do-dai-333-7" loading="lazy">Xăng-ti-mét viết tắt là <strong>cm</strong>.</p> <p>Bút chì dài <strong>5 cm</strong>.</p> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/342-1662094435.png.webp" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-8" title="hinh-anh-bai-26-don-vi-do-do-dai-333-8" loading="lazy"></p> <h3 id="hoat-dong">Hoạt động</h3> <h4>1. Bạn nào đặt thước đo đúng?</h4> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/343-1662094470.png.webp" width="580" height="262" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-9" title="hinh-anh-bai-26-don-vi-do-do-dai-333-9" loading="lazy"></p> <h4>2.</h4> <p>a) Đo độ dài mỗi cây bút.</p> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/344-1662094488.png.webp" width="538" height="181" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-10" title="hinh-anh-bai-26-don-vi-do-do-dai-333-10" loading="lazy"></p><div> <div class="ads-horizontal-wrapped">
<span class="ads-title">Advertisement</span>
<script async="" src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-8123786206223951" crossorigin="anonymous" type="text/javascript" data-checked-head="true"></script>

<ins class="adsbygoogle" style="display: block; height: 280px;" data-ad-client="ca-pub-8123786206223951" data-ad-slot="2203391893" data-ad-format="auto" data-full-width-responsive="true" data-adsbygoogle-status="done"><div id="aswift_3_host" style="border: none; height: 280px; width: 741px; margin: 0px; padding: 0px; position: relative; visibility: visible; background-color: transparent; display: inline-block;"></div></ins>
<script type="text/javascript">
            (adsbygoogle = window.adsbygoogle || []).push({});
        </script>
</div>
</div>b) Trong các cây bút trên, bút nào dài nhất, bút nào ngắn nhất?<p></p> <h4>3. Ước lượng độ dài mỗi cây bút rồi dùng thước có vạch chia xăng-ti-mét để đo chúng.</h4> <p>a)<img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/351-1662094542.png.webp" width="253" height="55" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-11" title="hinh-anh-bai-26-don-vi-do-do-dai-333-11" loading="lazy"></p> <p>Ước lượng: ... cm</p> <p>Đo độ dài: ... cm</p> <p>b)<img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/352-1662094562.png.webp" width="199" height="54" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-12" title="hinh-anh-bai-26-don-vi-do-do-dai-333-12" loading="lazy"></p> <p>Ước lượng: ... cm</p> <p>Đo độ dài: ... cm</p> <p>c)<img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/353-1662094576.png.webp" width="343" height="58" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-13" title="hinh-anh-bai-26-don-vi-do-do-dai-333-13" loading="lazy"></p> <p>Ước lượng: ... cm</p> <p>Đo độ dài: ... cm</p> <p>d)<img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/354-1662094587.png.webp" width="520" height="55" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-14" title="hinh-anh-bai-26-don-vi-do-do-dai-333-14" loading="lazy"></p> <p>Ước lượng: ... cm</p> <p>Đo độ dài: ... cm</p> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/355-1662094604.png.webp" width="699" height="82" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-15" title="hinh-anh-bai-26-don-vi-do-do-dai-333-15" loading="lazy"></p><div> <div class="ads-horizontal-wrapped">
<span class="ads-title">Advertisement</span>
<script async="" src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-8123786206223951" crossorigin="anonymous" type="text/javascript" data-checked-head="true"></script>

<ins class="adsbygoogle" style="display: block; height: 280px;" data-ad-client="ca-pub-8123786206223951" data-ad-slot="2203391893" data-ad-format="auto" data-full-width-responsive="true" data-adsbygoogle-status="done"><div id="aswift_4_host" style="border: none; height: 280px; width: 741px; margin: 0px; padding: 0px; position: relative; visibility: visible; background-color: transparent; display: inline-block;"></div></ins>
<script type="text/javascript">
            (adsbygoogle = window.adsbygoogle || []).push({});
        </script>
</div>
</div><p></p> <h4>4. Mỗi băng giấy dài bao nhiêu xăng-ti-met?</h4> <p><img style="display: block; margin-left: auto; margin-right: auto;" src="/uploads/tinymce/356-1662094626.png.webp" width="744" height="301" alt="hinh-anh-bai-26-don-vi-do-do-dai-333-16" title="hinh-anh-bai-26-don-vi-do-do-dai-333-16" loading="lazy"></p>