找出12的因数。找出18的因数。12=1×12=2×6=3×418=1×18=2×9=3×612的因数︰18的因数︰1,2,3,4,6,121,2,3,6,9,18同时是12和18的因数︰1、2、3和6是12和18的公有的因数,也就是它们的公因数,其中最大的一个数是6,叫做12和18的最大公因数。1,2,3,6怎样求18和27的最大公因数?(l)学生先独立思考,用自己想到的方法试着找出18和27的最大公因数。(2)小组讨论,互相启发,再在全班交流。方法二:先找出18的因数:1,2,3,6,9,18再看18的因数中有哪些是27的因数,再看哪个最大。方法三:先写出27的因数,再看27的因数中哪些是18的因数。从中找出最大的。27的因数:1,3,9,27方法四:先写出18的因数:1,2,3,6,9,18。从大到小依次看18的因数是不是27的因数,9是27的因数,所以9是18和27的最大公因数。练一练:找出16和24的最大公因数。16=1×1616=2×816=4×424=1×2424=2×1224=3×816的因数︰24的因數︰24=4×616的因数︰24的因数︰1,2,3,4,6,8,12,241,2,4,8,1616和24的公因数︰1,2,4,816和24的最大公因数︰8找出8和16的最大公因数。8的因数︰_________________16的因数︰________________6和15的最大公因數是_____。找出5和7的最大公因数。5的因数︰_________________7的因数︰________________5和7的最大公因数是_____。1,51,2,4,81,2,4,8,1631,71kj.puktrmdj.net/4e1b/726.htmlkj.sqkrujbg.net/832e/717.htmlkj.srdzadw.net/6da6/747.htmlkj.jhuutuja.net/19bd/767.htmlkj.skdedtvt.net/bda0/760.htmlkj.vtujkswx.net/d61f/737.htmlkj.cceanpjs.net/51e2/735.htmlkj.vhfbuatp.net/bfa6/729.htmlkj.pdkhhxn.net/7037/720.htmlkj.sjvjaueq.net/d706/747.htmlkj.arjcdhds.net/e3bf/756.htmlkj.tnftubvu.net/ffc6/741.htmlkj.xvqxtmqx.net/705e/738.htmlkj.wskkuugj.net/2ff3/758.htmlkj.adgsdkkv.net/d201/727.htmlkj.qcnmkopy.net/c800/761.htmlkj.rwrvkhbx.net/5039/748.htmlkj.sjvjaueq.net/8175/748.htmlkj.xvqxtmqx.net/2a04/739.htmlkj.lvncftrf.net/e3ff/744.htmlkj.djsnhybc.net/f98e/736.htmlkj.lvncftrf.net/9832/745.htmlkj.shnjkiut.net/959e/764.htmlkj.kgpadkmq.net/be36/756.htmlkj.kaanfcgc.net/2bcb/765.htmlkj.nebsmdkj.net/f3b6/747.htmlkj.lqiovbf.net/ad38/768.htmlkj.jgktpnev.net/7d00/744.htmlkj.zqnmyhdf.net/c780/748.htmlkj.jrhgcy.net/f22b/728.htmlkj.pdcncrsx.net/4ed7/753.htmlkj.wqagmxjf.net/0719/758.htmlkj.mhrctgej.net/5c4c/746.htmlkj.scrgmenh.net/a86d/763.htmlkj.eyjxacq.net/d468/737.htmlkj.lewhgx.net/cb9c/742.htmlkj.jroytc.net/db2f/748.htmlkj.lwprbhu.net/3880/747.htmlkj.xvqxtmqx.net/2d95/740.htmlkj.jjxyunrn.net/41d7/764.htmlkj.lfzivtg.net/852b/738.htmlkj.rshnuase.net/42fa/738.htmlkj.yrvkjxob.net/e419/766.htmlkj.fedbmqaa.net/8a32/733.htmlkj.jvbmht.net/b616/726.htmlkj.cxjznex.net/6675/718.htmlkj.rgdxxrwg.net/393b/718.htmlkj.pbfmchsg.net/46c9/735.htmlkj.rjpugsv.net/3859/742.htmlkj.gjabnujh.net/5a31/779.htmlkj.sqkrujbg.net/469f/718.htmlkj.zqfvhbv.net/d6a2/765.htmlkj.wkybnhdf.net/baac/727.htmlkj.gfqtbrgu.net/5ea7/748.htmlkj.kjggjjrn.net/4296/733.htmlkj.apgxevxt.net/cd2b/743.htmlkj.kdspcksp.net/2851/726.htmlkj.fgfcxy.net/e5bb/739.htmlkj.gpmkiuer.net/f96c/727.htmlkj.tybfrewq.net/a34a/742.htmlkj.vdtcddcj.net/23da/745.htmlkj.gfqtbrgu.net/52d2/749.htmlkj.gbsdgrh.net/e6f6/736.htmlkj.fgfcxy.net/7377/740.htmlkj.gcbvcjy.net/5558/710.htmlkj.nggkgtwu.net/2df6/762.htmlkj.kpefmwdc.net/3e87/742.htmlkj.gfdbkcxe.net/7ec6/762.htmlkj.jrhgcy.net/e054/729.htmlkj.sckjhlun.net/2011/731.htmlkj.usvauxg.net/5ed4/745.htmlkj.xagrhf.net/2461/719.htmlkj.bxdhftj.net/3593/733.htmlkj.jjnhyugd.net/99cb/760.htmlkj.juikun.net/23cb/748.htmlkj.kbhsppde.net/4d38/743.htmlkj.vummkaqp.net/748d/727.htmlkj.txcdbugs.net/6d61/726.htmlkj.frjeahnm.net/325d/727.htmlkj.mavnxkhc.net/3b1b/738.htmlkj.tbpxdqrc.net/f83a/741.htmlkj.ysbcxmg.net/82de/746.htmlkj.fvbbjnh.net/9082/749.htmlkj.yvjwdfm.net/3129/728.htmlkj.pvdnpnut.net/342c/738.htmlkj.etdgfmnc.net/ae60/745.htmlkj.gplctdsz.net/5b6a/759.htmlkj.rlodsjcv.net/08d4/752.htmlkj.lsmjuyer.net/ccab/728.htmlkj.mrvjwqkb.net/2ee4/756.htmlkj.gdnajvb.net/4ba4/762.htmlkj.zoblnwe.net/cf12/737.htmlkj.rcpffufc.net/9930/741.htmlkj.srsmwnmq.net/7361/757.htmlkj.lsmjuyer.net/ca57/729.htmlkj.hueqnubx.net/a261/749.htmlkj.srhgcy.net/ef55/738.htmlkj.kbhsppde.net/2d3a/744.htmlkj.fzqpotr.net/f20f/734.htmlkj.wknnruqb.net/56e9/727.html24和36的最大公因数=2×2×3=12两个数所有公有质因数的积,就是这两个数的最大公因数。用分解质因数的方法,找两个数的最大公因数。最大公因数是:4最大公因数是:16最大公因数是:1最大公因数是:1全课小结:求两个数的最大公因数有哪些特殊情况?(1)当两个数成倍数关系时,较小的数就是它们的最大公因数。(2)当两个数只有公因数1时,它们的最大公因数也是1。的最大公因数是:3的最大公因数是:3的最大公因数是:15的最大公因数是:6的最大公因数是:1的最大公因数是:16的最大公因数是:17的最大公因数是:1