《四年級(jí)數(shù)學(xué)下冊(cè)第6單元小數(shù)的加法和減法小數(shù)的加法和減法課件新人教版.ppt》由會(huì)員分享,可在線閱讀,更多相關(guān)《四年級(jí)數(shù)學(xué)下冊(cè)第6單元小數(shù)的加法和減法小數(shù)的加法和減法課件新人教版.ppt(20頁(yè)珍藏版)》請(qǐng)?jiān)谘b配圖網(wǎng)上搜索。
1、,小數(shù)的加法和減法(一),,2004 雅典奧運(yùn)會(huì),,兩名17歲的小將勞麗詩(shī)和李婷聯(lián)手為中國(guó)代表團(tuán)奪得了 本次比賽的第三枚跳水金牌,她們的成績(jī)?yōu)?52.14分。 這也是中國(guó)代表團(tuán)在本次奧運(yùn)會(huì)上摘得的第十枚金牌。,,2004雅典奧運(yùn)會(huì) 跳水比賽,勞麗詩(shī) 李 婷,,,中國(guó)隊(duì)領(lǐng)先3.6分。,53.40,49.80,,53.4049.80?,筆 算,3.6,5 3 . 4 0,,4 9 . 8 0,,0,6,列堅(jiān)式:,小數(shù)點(diǎn)要對(duì)齊,,3,.,,小數(shù)部分末尾有0,一般要把0去掉。,,,中國(guó)隊(duì)兩輪的總成績(jī)是多少?,53.40,49.80,58.20,49.20,,53.40+58.20?,筆 算,111.6
2、,5 3 . 4 0,+,5 8 . 2 0,,0,6,列堅(jiān)式:,小數(shù)點(diǎn)要對(duì)齊,,1,.,,小數(shù)部分末尾有0,一般要把0去掉。,1,1,,,現(xiàn)在中國(guó)隊(duì)領(lǐng)先多少分?,53.40,49.80,58.20,49.20,,,根據(jù)下面數(shù)據(jù)你能提出什么問(wèn)題?,53.40,49.80,58.20,49.20,82.80,71.04,86.70,327.78,352.14,76.60,76.70,75.48,,試著計(jì)算下面各題。,12.424.36,7.813.735,,12.424.36,7.813.735,小數(shù)點(diǎn)對(duì)齊,就是每個(gè)數(shù)位對(duì)齊。,數(shù)位上沒(méi)有數(shù)可以添“0”后再進(jìn)行計(jì)算。,0,0,,小數(shù)加減法要注意什
3、么?,小數(shù)點(diǎn)要對(duì)齊,也是把數(shù)位對(duì)齊。,得數(shù)的末尾有0,一般要把0去掉。,數(shù)位上沒(méi)有數(shù)可以添“0”后再進(jìn)行計(jì)算。,,小數(shù)的加減法也可以用計(jì)算器計(jì)算。,這就是 小數(shù)點(diǎn)鍵。,,口算,比比看,誰(shuí)算得又對(duì)又快。,3.6+1.4,5.7-2.3,7.6-3.1,4.9+0.5,6.2-2.4,4.9+1.5,0.26+0.35,0.93-0.58,0.37+14.3,,,,計(jì) 算,,一個(gè)書包的價(jià)格是65.8元,一個(gè)文具盒的價(jià)格是12.6元,這兩樣?xùn)|西一共多少錢?,我的50米賽跑成績(jī)是8.35秒。,,我的成績(jī)是8.52秒,我比你慢多少呀?,,計(jì)算小數(shù)加、減法,先把各數(shù)的小數(shù)點(diǎn)對(duì)齊(也就是把相同數(shù)位上的數(shù)對(duì)齊),再按照整數(shù)加減法的法則進(jìn)行計(jì)算,最后在得數(shù)里對(duì)齊橫線上的小數(shù) 點(diǎn),點(diǎn)上小數(shù)點(diǎn)。,小數(shù)加減法,謝謝使用!,,