蘇教版數(shù)學(xué)四年級(jí)下冊(cè)課件圖形的平移和旋轉(zhuǎn)2

四年級(jí)數(shù)學(xué)下冊(cè)課件（蘇教版）第一單元

平移、旋轉(zhuǎn)和軸對(duì)稱圖形的平移和旋轉(zhuǎn)1、進(jìn)一步認(rèn)識(shí)圖形的旋轉(zhuǎn)，認(rèn)識(shí)按順時(shí)針或逆時(shí)針方向旋轉(zhuǎn)90o的含義。2、能在方格紙上把簡(jiǎn)單圖形旋轉(zhuǎn)90o，畫出旋轉(zhuǎn)后的圖形。3、掌握旋轉(zhuǎn)的三要素。學(xué)習(xí)目標(biāo)從這幅圖中你看到了哪些運(yùn)動(dòng)？探究新知大家認(rèn)真自學(xué)書上第3頁(yè)的例2，并思考下面的問題（5分鐘）導(dǎo)學(xué)問題：1、圖中的轉(zhuǎn)桿打開和關(guān)閉分別是怎樣運(yùn)動(dòng)的？有什么相同點(diǎn)和不同點(diǎn)？2、轉(zhuǎn)桿的打開和關(guān)閉，分別繞哪個(gè)點(diǎn)按什么方向旋轉(zhuǎn)的?旋轉(zhuǎn)了多少度？3、你能完整地描述轉(zhuǎn)桿打開和關(guān)閉的過程嗎？探究新知轉(zhuǎn)桿打開和關(guān)閉，它們的運(yùn)動(dòng)有什么相同點(diǎn)和不同點(diǎn)？相同點(diǎn)：轉(zhuǎn)桿打開和關(guān)閉都是繞著一個(gè)點(diǎn)旋轉(zhuǎn)。不同點(diǎn)：轉(zhuǎn)桿打開和關(guān)閉旋轉(zhuǎn)的方向正好相反。探究新知與時(shí)針旋轉(zhuǎn)方向相同的是順時(shí)針，與時(shí)針旋轉(zhuǎn)方向相反的是逆時(shí)針。探究新知轉(zhuǎn)桿關(guān)閉的方向與時(shí)鐘轉(zhuǎn)動(dòng)方向一致嗎？轉(zhuǎn)桿打開的方向與時(shí)鐘轉(zhuǎn)動(dòng)方向一致嗎？順時(shí)針方向逆時(shí)針方向探究新知從6：00到9：00，時(shí)針旋轉(zhuǎn)了（）。。90探究新知A你會(huì)把右邊的三角板繞A點(diǎn)旋轉(zhuǎn)90。嗎？探究新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探究新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探究新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知A把三角板繞A點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知旋轉(zhuǎn)有哪三要素？1、旋轉(zhuǎn)中心。（繞某點(diǎn)）2、旋轉(zhuǎn)方向。（順時(shí)針或逆時(shí)針）3、旋轉(zhuǎn)角度。（旋轉(zhuǎn)90度或其他角度）完整描述旋轉(zhuǎn)：某圖形繞某點(diǎn)順時(shí)針（或逆時(shí)針）旋轉(zhuǎn)多少度。如三角形繞點(diǎn)A逆時(shí)針旋轉(zhuǎn)90°。探索新知AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。探索新知AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。AB把長(zhǎng)方形繞A點(diǎn)順時(shí)針旋轉(zhuǎn)90。把小旗圖繞B點(diǎn)逆時(shí)針旋轉(zhuǎn)90。ABCD指針按順時(shí)針方向旋轉(zhuǎn)90。，從A旋轉(zhuǎn)（）；指針按逆時(shí)針方向旋轉(zhuǎn)90。，從B旋轉(zhuǎn)（）。ABCDBA錯(cuò)誤解答錯(cuò)解分析：與時(shí)針旋轉(zhuǎn)方向相同的是順時(shí)針方向，與時(shí)針旋轉(zhuǎn)方向相反的是逆時(shí)針方向。ABCD指針按順時(shí)針方向旋轉(zhuǎn)90。，從A旋轉(zhuǎn)（）；指針按逆時(shí)針方向旋轉(zhuǎn)90。，從B旋轉(zhuǎn)（）。ABCDABCDABCDDC正確解答你見過生活中的哪些旋轉(zhuǎn)現(xiàn)象？你能說出來嗎？旋轉(zhuǎn)有哪三要素？1、旋轉(zhuǎn)中心。（繞某點(diǎn)）2、旋