二年级升三年级数学知识小结

1、one"and theimprovement ofoverall scheme of reform,will promnofthe Standing Committeeofthepoliti calBureaheCentralCommittee members, decisions,such as membersoftheCe ntralMilitary Commission.Thesecond ple naryse ssion,is held intwose ssi onsbeforethege neralele ction,mainlyto discussa newStatepe

2、rsonnelissues. But by t hethirdcoordinate d economic, politig cultural ,socivalatplo 1o2rte phu.b3l5iyearscasgeorvbalentws'duty tchoentsuhmirdpti. 一一.-I, _ Ll civilizationconstruction oftheparty'sconstri ng breei on in theare a ofinstit utionalreform.The"five in one"programme istoa

3、chi evea comprsmoot h pron of awell-offsociety and reform theonSohfadmutyShcuoinPsuomDpitiostobje ctives ofthepr ogramme.ceimportance onNovember 9,2013 to the18seh Beijing since 1978,35,havebeen 7 plecountrysi -oes;research "villagentralCommittee in aplenarysessi on washeld immediatelyafterthep

4、arty'sCongress,onthe theme"personnel",discussi ng ele ctionCentral'stop lea ders,二年级升三年级数学一、数学知识点（一）两位数加法，要记三条1、相同数位对齐；2、从个位加起；3、个位满10 向十位进1 。（二）笔算两位数减法，要记三条1、相同数位对齐；2、从个位减起；3、个位不够减从十位退1，在个位加10 再减。（三）四位数的读法1、从高位起按顺序读，千位上是几读几千，百位上是几读几百，依次类推；2、中间有一个0 或两个 0 只读一个“零”；3、末位不管有几个0 都不读。（四）四

5、位数写法1、从高位起，按照顺序写；2、几千就在千位上写几，几百就在百位上写几，依次类推，中间或末尾哪一位上一个也没有，就在哪一位上写“0”。（五）解答应用题步骤1、弄清题意，并找出已知条件和所求问题，分析题里的数量关系，确定先算什么，再算什么，最后算什么；2、确定每一步该怎样算，列出算式，算出得数；3、进行检验，写出答案。二、数学口决定义归类1、加法各部分的关系：一个加数=和 - 另一个加数2、减法各部分的关系：减数=被减数- 差被减数=减数+差3、乘法各部分之间的关系：一个因数=积+另一个因数4、除法各部分之间的关系：除数=被除数+商被除数=商>< 除数5、角（ 1 ）什么是角？

6、从一点引出两条射线所组成的图形叫做角。（ 2）什么是角的顶点？围成角的端点叫顶点。（ 3）什么是角的边？二年级数学知识点小结围成角的射线叫角的边。（ 4）什么是直角？度数为90°的角是直角。（ 6）什么是锐角？小于90 °的角是锐角。（ 7）什么是钝角？大于90°而小于180°的角是钝角。6、什么是四舍五入法？求一个数的近似数时，看被省略的尾数最高位上的数是几，如果是4 或者比 4 小，就把尾数舍去，如果是 5 或者比 5 大，去掉尾数后，要在它的前一位加 1 。这种求近似数的方法，叫做四舍五入法。7、加法意义和运算定律（ 1）什么是加法？把两个数合并成

7、一个数的运算叫加法。（ 2）什么是加数？相加的两个数叫加数。（ 3）什么是和？加数相加的结果叫和。8、什么是减法？已知两个数的和与其中的一个加数，求另一个加数的运算叫做减法。9、什么是被减数？什么是减数？什么叫差？在减法中已知的和叫被减数，减去的已知数叫减数，所求的未知数叫差。10 、加法各部分间的关系：和 =加数+加数加数 =和 -另一加数11、减法各部分间的关系：差 =被减数- 减数减数=被减数-差被减数=减数+差12 、乘法（ 1）什么是乘法？求几个相同加数的和的简便运算叫乘法。（ 2）什么是因数？相乘的两个数叫因数。（ 3）什么是积？因数相乘所得的数叫积。13 、除法（ 1）什么是除法

8、？stmarketeconomy.Previousple nary sessiontopics propose dto thethird plenary sessi on of"taking class struggleast hekey link," shifted to socialist modernization;12session marked t he changefrom ruraltourba n, esta blishedwit hpubliclenary sessi on,e achsession oftheCe ntral Committeeofnat

9、ionalinstituti onsand personnelpr oblem s have beenarra nged,youca nconcentrateon nati onal developmenta nd reforms.Previousple nary se ssion isofte n brandedw ith acentralleadi ng collective ,oftenbyl ooki ng atthe thir d plenum ofthe init iative t ofoundthe curre nt central lea dership collectiveg

10、over nance characteristi cs.Fromthe analysis of theprocess ofeconomicreform i n Chi na, plenary sessi on, 12session,14, 16plenaryse ssion have programmaticmeani ng,respective ly, marking t hefour stage sofChi na'seconomi c reform,and t hatthestart-up phase ofreform,reform,constructionphase and p

11、erfe cting theS13session at atime whe n both t he ol d and theectivcehcaonorisdmi sforthenationofpower restrictinew systemnance aa nd re ctifythe economicngthe n anti-corr uptii on ionrsdtietur;ti14 .Fairandefficientand aut horitativeSocialistjudi cialsystem, safeguard t hepeople'sinterests.onal

12、 innovationa nd i nstituti onal protecti on, sound improveme ntstyle normal system.Plenary session, builofadministrativelaweer, must adhereto thenforceme nt, ensuret hatthe rig httoexerciseorientati on ofa dvanced Socialist culturjudicial power indepe nder e,adhere to thedevelopmeh Chi nesecharacter

13、isting mechanism ofjudi cialpowe r,improvet hesystem ofjudics,a dheret othe people-centre d work -orie nted,furtherdee pening reform ofculture.cialpr otection ofhumao improvethecultnrights.I sh a nd imprdheretotheuthoritytoletthe pow errun inthe Sun,is shutding modern public culturalservicesystem,im

14、provetup i n acage ofthesystem power polihelevelofcultureopening.Plecy. DecisionScie nce , impleme ntation shoul dbenary session, achievi ngdevel opmentre sultsmoreequitableg ofpowerfulsystem,improvethe system of punishing a nd preventingcorrng politicaliachievend bettermeetcoordinate d economic, po

15、litig cultural ,socivalang breeutionalreform.The"five in one"programme istoachi evea comprsmoot h pron of awell -offsociety and reform theobje ctives ofthepr ogramme.One,holdiceimportance onNovember 9,2013 to thce,ofte nateverysession oftheCPCCentralCommittee in aplenarycountrysi -sessi on

16、 washeld immediatelyaftertheparty'sCongress,onthe theme"personnel",discussi ng ele ctionCentral'stop lea ders,已知两个因数的积与其中的一个因数，求另一个因数的运算叫除法。（ 2）什么是被除数？在除法中，已知的积叫被除数。（ 3）什么是除数？在除法中，已知的一个因数叫除数。（ 4）什么是商？在除法中，求出的未知因数叫商。14、乘法各部分的关系：积=因数X因数一个因数=积+另一个因数15、（1 ）除法各部分间的关系：商=被除数+除数除数=被除数+商（ 2

17、）有余数的除法各部分间的关系：被除数=商>< 除数+余数三、小学数学量的计算单位及进率归类1 、长度计量单位及进率：千米（公里）、米、分米、厘米、毫米1 千米 =1 公里1 千米 =1000 米1 米 =10 分米 1 分米 =10 厘米 1 厘米 =10 毫米2、质量单位及进率：吨、千克、公斤、克1 吨 =1000 千克1 千克 =1 公斤1 千克 =1000 克3、时间单位及进率：世纪、年、月、日、小时、分、秒1 世纪 =100年 1 年 =12月 1 天 =24小时 1 小时 =60 分 1 分 =60 秒（ 31 天的月份有1、 3、 5、 7、 8、 10、 12 月份，

18、30 天的月份有4、 6、 9、 11 月份，平年 2 月 28 天，闰年2 月 29 天）应用题解法一、加法（ 1 ）求总数的应用题：例：商店有苹果15 千克，梨8 千克，请问梨和苹果一共有多少千克？15+8=23（千克）答：梨和苹果一共有23 千克。（ 2）求比一个数多几的数的应用题例：商店有苹果15 千克，梨比苹果多8 千克，请问梨有多少千克？15+8=23（千克）答：梨有23 千克。二、减法（ 1 ）求剩余的应用题例：把一个西瓜切成8 块， 3 块给爸爸，3 块给妈妈，剩下的留给小红，请问小红分到几块西瓜？8-3-3=2（块）答：小红分到2 块西瓜。（ 2）求两个数相差多少的问题例：商

19、店有苹果15 千克，梨8 千克，请问苹果比梨多多少千克？15-8=7（千克）答：苹果比梨多7 千克。（ 3）求比一个数少几的数的应用题例：晓航有15 支铅笔，李红比晓航少8 支，请问李红有多少支铅笔？15-8=7（支）答：李红有7 支铅笔。小结（1） A比B多，已知B,求A?（加法）（2） A比B多，已知A,求B?（减法）（3） A比B少，已知B,求A?（减法）lenary sessi on,ea ch sessi on oftheCe ntral Committeeofnationalinstituti onsa nd personnel problemshavebee narrange d

20、,you can conce ntrateon nationaldevel opme ntand reforms.Previouspl enary se ssion is often brande dwith a centralleadi ngcollective ,oftenbyl ooki ng atthe third plenum ofthe i nitiativetofoundthe currentcentralleader shi pcoll ectivegover nance characteri stics.Fromthe analysis of theprocess of ec

21、onomicreform inChina, pl enaryse ssi on, 12session, 14,16 ple narysession havepr ogrammaticmeaning, respectively, marking thefourstages ofChina'seconomic reform,astmarketeconomy.Previousple nary sessiontopink,"shi fted to socia listm odernizati on;12 session marked thechange fromruralto urb

22、a n,esta blished wit hpubliowner shi p as theFoundation ofa plannedcommodity economy;13 session atatime when bot hthe oldand theconomic order ;14 . Fairand efficientand a uthoritative Sociali stjudicialsystem, safeguard the pe ople' s interests.Legalauthorityto uphol d theConstitution,deepe ning

23、 t he reform ofadministrative lawenforceme nt, ensurethatthe righttoexercise judicialcadres 'hone st andGover nment integrit y,clean politics.Toform ascientific a nd effective coor dinati onofpower restri ctionand mecha nismst ostrengthen anti -corruption institutional innovation andinstitutiona

24、l prote ction,sound improvementstyle normal system.Ple nary session, buil ding asociali st cult urein Chi na,enhancing nationalcultural soft power, must a dhere t o theori entation of advanced S ociali stcult ure, apower i ndepe nde ntly andimpartiallyaccording to law t hepr osecution,perfectingthe

25、runningmeh Chinesecharacteristi cs,a dheret othe people-centrecha nismofjudicial pow er,impr ove thesystem ofjudid work-orie nted,furtherdee peni ng reformofcultcialprote ction of humaure.o improve thenrights.Pl enary sessi on,Affairstherighttoadher etothe system, a ndletthe pe opleacult uralmanagem

26、ent sy stem,establishand improvethe modern market systemand buildiuthority to letthepowerrng moder npubliunint he Sun,isshut up in acculturalservi ce system, impra cage ofthesystem power policy.Deci sion Scie nce, im plementationshould beconstructeovethe level ofcult ure openi ng. Ple nary se ssion,

27、 a chievi ngdevel opment results moreong, supervisethe runningequitable benefitofallpeople,we mustof pow erfulsystem,i mprove thesystem ofpunishi ngand preventi ng corrupti on, promoti ng political integrit y,andstrive to a chievespee d upreform ofsocial programsa nd solve thei ssuesofconcern to the

28、peoplet he most directand real interest,and better meetrapid deve lpme nt of Ie market economy ev.nment toexpl ore publ c sevas ' dUy cnsmpl onmonetizti .nefomhas provded a good .-in. ThescazainofreaserviceworkhasbeeauCed,andapidprogessisomeplacesanddepartment, duty cnsump.onmon.ainofrie a I d a

29、pr oac to maageme nthas b- res d. Thir d,i re cent yeas, explri ng the monelal on of duty consumpin hasmadesomeprogress,haveganedsome expei ence ad n provide refeece to thecmpehensive reorm of Ie sys_ of publcservants'_y Implementiga."on nten", sa n-r dze olcl_ e nteaii ng maageme nt；

30、ehacig t he teecmmui in exe nse maag emet； e.i naton of Ccuty travel ad cuntrysi de sus dies reseach "vlage olcals"cap.onmanaggmetof crporae spe I di ng, a nd s on. F.a、ggoup.18 sesin I be hed i n Bijng fom N<embe 9 203 I ”. yas ,oblewthe| enay efmandopeing springbrrez,change_alecteworl

31、_toayyeasaerithe.oftenainadtewoldexpec,.a ntefm mak Cci n* usee d ite 18 ssson. X Genea Se c，ay poied out ta CCi nas efm ha s enteed a cu cil pe,d Id te Shhm Shui Po Disrc,mustbebasdongerpoltclcurgeand Wsddm, Ise no -e ideeeingreormiimporantfedsDaestocackahadnu,daestoqqesinteRapis, wic daes t o brra

32、kthe barie of idas a nd dae I benei cue bari es. De epe ling efm ad opei ng us onsce d- t o ac isBuina adsofthemooeaKyweloflUnderte"veionn"theGeea11youtofscUi st mode nizai on requ - ment s, 8 on of te .e csi on a "ie i one" ad the m pr<eme shemeofrfm,wlprmoeai、r d and cord na

33、td e conomi c poltcl cul url scia a nd e col ogca civlzai in cnstucin of the fve rfrms ad thepays cnstuct on in the ara of intt uina efm.The"fveionn"progammestoacieveacompehesieefmofinsiutonaglaee s for objct iesof buid a wel of scey Ie - oot progres of Ie constucon of a welofscieyandefmth

34、eobectvlsoftheprogrrmme.OneholingtimeadpacemporaceonN<embe 9 ! toIe8lesion of Ie 2tBe.gsine17835ha- be e - pleay on, ct me on majr i sluls of polica and ecnomic le of IecutyhasmademporatdeloomentInaccdancewtPR-po.ica pacic, ofte a eeyle n of Ie CPCCeeta C.mm.te in a pleayonwashedimmedaeyakr the p

35、arys Conges, on the thme "esnne", dic - sig eectonCentalsIpledessuchasIe e icton of Ie Sa ndi ng C.mmieeof the poiicaBulau, tr oug岸林未卜习出jlIe Cental Ccmmiee m bes,decisons such as m_ber s of the Ce nta Miltay C.mmi I n.Ie secnd pl eay se ssn, s he d iwo sesions b.ore the .nea eecton, manly

36、to discss a ne w Stae pesonne -us.Bu by t he ti,、 B''I'J I（4） A比B少，已知A,求B?（加法）三、乘法（1）求相同加数的和的应用题例：3个5是多少？ （ 3 X 5=15）（2）求一个数的几倍是多少的应用题例：桃树有5棵，梨树是桃树的三倍，那么梨树有多少棵？5X 3=15（棵）答：梨树有15棵四、除法（1）把一个数平均分成几份，求每一份是多少的问题例：妈妈买了 15个苹果，平均分到3个篮子，请问每个篮子分到几个苹果？15+3=5（个）答：每个篮子分到 5个苹果。（2）求一个数里包含几个另一个数的应用题例：请问

37、15里面包含几个 5? （15+5=3）（3）求一个数是另一个数的几倍的应用题例：晓明买了 24支铅笔，6支圆珠笔，请问铅笔是圆珠笔的几倍？24+ 6=4答：铅笔是圆珠笔的4倍。小结：（1） A是B的N倍，已知A,求B?（除法B=A+ N）*（2） A是B的N倍，已知B,求A?（乘法A=BX N）*三年级上册知识点第1单元 测量1、生活中，量比较短的物品，可以用（ 毫米、厘米、分米 ）做单位；量比较长的物体，常 用（米）做单位；测量比较长的路程一般用（ 千米）做单位，千米也叫（ 公里）。2、1厘米的长度里有（10 ）小格，每个小格的长度（ 相等），都是（1 ）毫米。3、1枚1分的硬币、尺子、磁

38、卡、小纽扣、钥匙的厚度大约是1毫米。4、在计算长度时，只有相同的长度单位才能相加减。小技巧：换算长度单位时，把大单位换成小单位就在数字的末尾添加0（关系式中有几个 0,就添几个0）;把小单位换成大单位就在数字的末尾去掉0 （关系式中有几个 0,就去掉几个0）。5、长度单位的关系式有：（每两个相邻的长度单位之间的进率是10 ）进率是101米=10 分米 1 分米=10 厘米 1 厘米=10 毫米ese c esetl it Ilstti s l ea eaaga c c taail dela e sPev s iit a d- etl ldglctv ekg tri t iv c itl lae

39、 s leige a c . tcsF alyites cfa 11s ss 2esi 4 6l sei agaHaigecfl- a g 11tge e i ma t a u s e e m s uct arcigake faewk sagsialsakec .Peruaesisisst- .ls-atkeksfe t s i li e a2 sei a k c a gfultustlsein l c y3 r ihttl syc >gea i yci d - Fi alficlu iav Sial t ussagudte inessgltisttoig e aittvlf cu a

40、1gt enisuiawedl aiar-acig tact nrciguigc is jdiaiv-s uiaigtp y ifir c.syltliitnui Siic.-sw-esin entais1c tu sgsriuiglfysetyseusgelgcugla git y atv tcivcdeG e gica 1tsseiiIfcv cite cia ci11gt 1at cuiiiua oaist1t cis i elm 1yse Pley i i ig 1rls cl i1cg llul s- e - me.ia ecascluee - ee lu iies - cesdee

41、lee-I k ie u te d1g ef , ltev tlt geeseeai i kt sya lg.ul a c syiv-lluegPleysiciigeveleale e a e tseu1aga1vtse ttlsdanesa-a -enne ds of -e propI dee educai on rfm, impml i nstut ona me chaniims fr -ecoordinate d economic, politig cultural ,socivalang breeutionalreform.The"five in one"count

42、rysi -ntralCommittee in aplenarysessi on washeld immediatelyaftertheparty'sCongress,onthe theme"personnel",discussi ng ele ctionCentral'stop lea ders,10 分米 =1 米 10 厘米 = 1 分米 10毫米 = 1 厘米 进率是 1001 米 = 100 厘米 1100 厘米 =1 米 100 进率是 10001 千米 =1000 米 1分米 =100 毫米毫米 =1 分米公里 = =1000 米1000 米

43、=1 千米1000 米 = 1 公里6、当我们表示物体有多重时，通常要用到（质量单位）。在生活中，称比较轻的物品的质量，可以用（克 ）做单位；称一般物品的质量，常用（千克 ）做单位；计量较重的或大宗物品的质量，通常用（吨 ）做单位。小技巧：在“吨”与“千克”的换算中，把吨换算成千克，是在数字的末尾加上 3 个 0；把千克换算成吨，是在数字的末尾去掉3 个 0。7、质量单位进率是1000（相邻）1吨=1000 千克1千克=1000克1000千克 =1 吨1000 克=1千克第 2 单元万以内的加法和减法1、数是三位数的连续退位减法的运算步骤： 列竖式时相同数位一定要对齐； 减法时，哪一位上的数不

44、够减，从前一位退1 ；如果前一位是0，则再从前一位退1。2、在做题时，我们要注意中间的0，因为是连续退位的，所以从百位退1 到十位当10 后，还要从十位退1 当 10，借给个位，那么十位只剩下9，而不是10。 （两个三位数相加的和可能是三位数，也有可能是四位数。）3、公式。被减数 =减数+差和=加数+另一个加数减数=被减数差加数 =和另一个加数差 =被减数-减数第 3 单元四边形1、有 4 条直的边和2、 四边形的特点：有四条直的边，有四个角。3、 长方形的特点：长方形有两条长4、 正方形的特点：有4 个角封闭图形我们叫它四边形。有四条直的边，有四个角。, 两条宽，四个直角，对边相等4 个直角

45、，4 条边相等。5、 长方形和正方形是特殊的平行四边形。6、平行四边形的特点：对边相等、对角相等。（三角形不容易变形）正方形的周长=边长X 4正方形的边长=周长+ 4平行四边形容易变形。7、 封闭图形一周的长度，就是它的周长8、公式。长方形的周长=（长+宽）X 2长方形的长=周长+ 2宽长方形的宽=周长+ 2长第 4 单元有余数的除法1、余数和除数之间的关系：进行有余数的除法计算时，结果中的余数一定要比除数小。lenary sessi on,ea ch sessi on oftheCe ntral Committeeofnationalinstituti onsa nd personnel p

46、roblemshavebee narrange d,you can conce ntrateon nationaldevel opme ntand reforms.Previouspl enary se ssion is often brande dwith a centralleadi ngcollective ,oftenbyl ooki ng atthe third plenum ofthe i nitiativetofoundthe currentcentralleader shi pcoll ectivegover nance characteri stics.Fromthe ana

47、lysis of theprocess of economicreform inChina, pl enaryse ssi on, 12session, 14,16 ple narysession havepr ogrammaticmeaning, respectively, marking thefourstages ofChina'seconomic reform,astmarketeconomy.Previousple nary sessiontopink,"shi fted to socia listm odernizati on;12 session marked

48、thechange fromruralto urba n,esta blished wit hpubliowner shi p as theFoundation ofa plannedcommodity economy;13 session atatime when bot hthe oldand theconomic order ;14 . Fairand efficientand a uthoritative Sociali stjudicialsystem, safeguard the pe ople' s interests.Legalauthorityto uphol d t

49、heConstitution,deepe ning t he reform ofadministrative lawenforceme nt, ensurethatthe righttoexercise judicialcadres 'hone st andGover nment integrit y,clean politics.Toform ascientific a nd effective coor dinati onofpower restri ctionand mecha nismst ostrengthen anti -corruption institutional i

50、nnovation andinstitutional prote ction,sound improvementstyle normal system.Ple nary session, buil ding asociali st cult urein Chi na,enhancing nationalcultural soft power, must a dhere t o theori entation of advanced S ociali stcult ure, apower i ndepe nde ntly andimpartiallyaccording to law t hepr

51、 osecution,perfectingthe runningmeh Chinesecharacteristi cs,a dheret othe people-centrecha nismofjudicial pow er,impr ove thesystem ofjudid work-orie nted,furtherdee peni ng reformofcultcialprote ction of humaure.o improve thenrights.Pl enary sessi on,Affairstherighttoadher etothe system, a ndletthe

52、 pe opleacult uralmanagement sy stem,establishand improvethe modern market systemand buildiuthority to letthepowerrng moderunint he Sun,isshut up in acculturalservi ce system, impra cage ofthesystem power policy.Deci sion Scie nce, im plementationshould beconstructeovethe level ofcult ure openi ng.

53、Ple nary se ssion, a chievi ngdevel opment results moreong, supervisethe runningequitable benefitofallpeople,we mustof pow erfulsystem,i mprove thesystem ofpunishi ngand preventi ng corrupti on, promoti ng political integrit y,andstrive to a chievespee d upreform ofsocial programsa nd solve thei ssu

54、esofconcern to thepeoplet he most directand real interest,and better meetrapid deve lpme nt of Ie market economy ev.nment toexpl ore publ c sevas ' dUy cnsmpl onmonetizti .nefomhas provded a good .-in. Thescazain of rea servi ce work has bee a uCe d, and api d proge ss i some pl aces a nd depart

55、me nt, duty cnsump.onmon.ain of rie a I d apr oac to maageme nthas b- res d. Thir d,i re cent yeas, explri ng the monelal on of duty consumpin has made some progress, have ganed some expeience ad n provide refeece to thecmpehe nsive reorm of Ie sys_ of publc servants ' _y Impl ementig a ."on nten", sa n-r dze olcl_ e nteaii ng maageme nt； ehacig t he teecmmui in exe nse maag emet； e.i naton of Ccuty travel ad cuntrysi de sus dies reseach "vlage olcals" cap. . onma naggmet of crporae spe I di ng, a nd s on. F.a、ggoup .18 sesin I be hed i n Bijng