人教版四年級數(shù)學(xué)下冊-1四則運(yùn)算-第3課時(shí)--有關(guān)0的運(yùn)算-課件
,人教版,數(shù)學(xué)四年級(下),四則運(yùn)算,第,3,課時(shí) 有關(guān),0,的運(yùn)算,1,學(xué)習(xí)目標(biāo),1,.,掌握關(guān)于,0,的,運(yùn)算,通過合作學(xué)習(xí),歸納,總結(jié),0,的特,性,,會,利用,0,的,特性進(jìn)行四則運(yùn)算。,2,.,體會,0,在,四則運(yùn)算中的地位和作用。,3,.,在分析歸納,過程中,,培養(yǎng)推理,、概括能力。,【,重點(diǎn),】,掌握,0,在四則運(yùn)算中的特性,。,【,難點(diǎn),】,理解,0,不能作,除數(shù)及其,原因。,課堂導(dǎo)入,比一比,看誰算得又快又對。,35,0=,75,0=,69+0 =,45,-,45=567-0=,336-336=,3250=0 28=72 0 =,35,75,69,0,567,0,0,0,0,35,0=,75,0=,69+0 =,45,-,45=567-0=,336-336=,3250=0 28=72 0 =,35,75,69,0,567,0,0,0,0,一個(gè)數(shù),加上,0,或,減去,0,,還得,原數(shù),。,觀察這些算式,你發(fā)現(xiàn)了什么?,探究新知,教材第,6,頁,35,0=,75,0=,69+0 =,45,-,45=567-0=,336-336=,3250=0 28=72 0 =,35,75,69,0,567,0,0,0,0,被減數(shù),等于,減數(shù),,差,是,0,。,觀察這些算式,你發(fā)現(xiàn)了什么?,35,0=,75,0=,69+0 =,45,-,45=567-0=,336-336=,3250=0 28=72 0 =,35,75,69,0,567,0,0,0,0,一個(gè)數(shù),和,0,相乘,,仍,得,0,。,觀察這些算式,你發(fā)現(xiàn)了什么?,35,0=,75,0=,69+0 =,45,-,45=567-0=,336-336=,3250=0 28=72 0 =,35,75,69,0,567,0,0,0,0,0,除以,任何,非,0,的數(shù),都得,0,。,觀察這些算式,你發(fā)現(xiàn)了什么?,0,在四則運(yùn)算中的,特性:,一個(gè)數(shù),加上,0,或,減去,0,,還得,原數(shù),。,被減數(shù),等于,減數(shù),,差,是,0,。,一個(gè)數(shù),和,0,相乘,,仍,得,0,。,0,除以,任何,非,0,的數(shù),都得,0,。,1,2,3,4,想一想:,0,能作除數(shù)嗎,?,?,0=5,50,不可能得到商,因?yàn)檎也坏揭粋€(gè)數(shù)同,0,相乘,得到,5,。,5 0=,?,無商,1,想一想:,0,能作除數(shù)嗎,?,00,不可能得到一個(gè)確定的商,因?yàn)槿魏螖?shù)同,0,相乘,都得,0,。,?,0=0,0 0=,?,商不確定,0,不能作除數(shù),2,左邊方格里的數(shù)排列是有規(guī)律的。請把和,是,34,0,的相,鄰,4,個(gè)數(shù)找出來,再用彩色筆圈出來??纯茨隳苷业綆捉M。,10,80,100,150,140,70,110,50,40,90,160,20,120,60,30,130,數(shù)學(xué),游戲,=340,橫著看,=340,=340,=340,教材第,6,頁“數(shù)學(xué)游戲”,10,80,100,150,140,70,110,50,40,90,160,20,120,60,30,130,=,豎著看,=,=,=,左邊方格里的數(shù)排列是有規(guī)律的。請把和,是,34,0,的相,鄰,4,個(gè)數(shù)找出來,再用彩色筆圈出來??纯茨隳苷业綆捉M。,數(shù)學(xué),游戲,340,340,340,340,10,80,100,150,140,70,110,50,40,90,160,20,30,130,=340,斜著看,=340,答案不唯一,左邊方格里的數(shù)排列是有規(guī)律的。請把和,是,34,0,的相,鄰,4,個(gè)數(shù)找出來,再用彩色筆圈出來??纯茨隳苷业綆捉M。,數(shù)學(xué),游戲,120,60,1,.,想一想,填一填。,課堂練習(xí),(,1,)一,個(gè)數(shù)除以(,),,仍得原數(shù)。,(,2,),(),不能作除數(shù)。,(,3,),0,除以一個(gè)非,0,的數(shù)還得(,),。,0,1,0,61=6,2,.,判斷。,(1,),除數(shù),和被除數(shù)是相同的數(shù)(零除外),商是,0,。,(,),(2,),減數(shù),和被減數(shù)是相同的數(shù),差是,0,。(,),(,3)0,除以任何數(shù)都得,0,。,(),99=1,0,除以任何非,0,的數(shù)都得,0,。,3,.,在里填上“”、“”或“,=”,。,127+0,129-0,567567,5671,340,9990 0 567,45-45,056,560 786+0,786-0,=,=,=,=,63-181,=0,(,塊,),答:他還剩下,0,塊。,先,求買了多少,塊。,=18-18,4,.,小林買了,6,盒巧克力,每盒有,3,塊,他把,這些,巧克力,分給,18,個(gè),好朋友每人,1,塊,,他還剩,多,少,塊?,同學(xué)們,這節(jié)課你有什么收獲?,課堂小結(jié),有關(guān),0,的運(yùn)算,02,01,03,一個(gè)數(shù),加上,0,或,減去,0,,還得,原數(shù),。,被減數(shù),等于,減數(shù),,差,是,0,。,一個(gè)數(shù),和,0,相乘,,仍,得,0,。,04,0,除以,任何,非,0,的數(shù)都,得,0,。,注意,0,不能作除數(shù)。,