人教版六年級數(shù)學(xué)下冊《數(shù)學(xué)思考》PPT
耳 朵 傾 聽 ,眼 睛 觀 察 ,嘴 巴 說 話 ,用 心 思 考 。打 一 個(gè) 字 ? 聰 數(shù) 學(xué) 思 考 巧 數(shù) 線 段 .小 組 內(nèi) 的 4個(gè) 同 學(xué) ,每 兩 個(gè) 握 一 次 手 ,一 共 可 以 握 幾 次 ? 思 考 : 怎 樣 做到 不 重 復(fù) , 不遺 漏 , 有 順 序 一 共 握 了 : 6次1+2+3=6(次 ) 8個(gè) 同 學(xué) 可 以 握 多 少 次 呢 ? 我 們教 室 里 的 40個(gè) 同 學(xué) 又 可 以 握 多 少 次 呢 ? 有沒 有 什 么 規(guī) 律 ? 我 們 可 以 從 2個(gè) 點(diǎn) 開 始 ,逐 步 增 加 點(diǎn) 數(shù) 來 研 究 。 also lack the necessary understanding.Two is the business foundation is not solid, the text level is not high. Their work in the army before, although the understanding of the material, but also just only know fur, text level, writing ability is still in a low level interface. The knowledge is not complete, especially it is very little about professional some departments know knowledge, to write Chinese but not false, sometimes rely on online writing or presentation of ready-made one-sided materials, unwilling to make a deep thinking, put all sorts of things together, the presentation quality is not high, due to the overall quality of their own quality is not high, the leadership of departments can not understand, it is difficult to stand in the perspective 小 組 合 作 要 求 : 連 一 連 , 完 成 表 格 說 一 說 你 們 的 發(fā) 現(xiàn) also lack the necessary understanding.Two is the business foundation is not solid, the text level is not high. Their work in the army before, although the understanding of the material, but also just only know fur, text level, writing ability is still in a low level interface. The knowledge is not complete, especially it is very little about professional some departments know knowledge, to write Chinese but not false, sometimes rely on online writing or presentation of ready-made one-sided materials, unwilling to make a deep thinking, put all sorts of things together, the presentation quality is not high, due to the overall quality of their own quality is not high, the leadership of departments can not understand, it is difficult to stand in the perspective A B also lack the necessary understanding.Two is the business foundation is not solid, the text level is not high. Their work in the army before, although the understanding of the material, but also just only know fur, text level, writing ability is still in a low level interface. The knowledge is not complete, especially it is very little about professional some departments know knowledge, to write Chinese but not false, sometimes rely on online writing or presentation of ready-made one-sided materials, unwilling to make a deep thinking, put all sorts of things together, the presentation quality is not high, due to the overall quality of their own quality is not high, the leadership of departments can not understand, it is difficult to stand in the perspective A BC also lack the necessary understanding.Two is the business foundation is not solid, the text level is not high. Their work in the army before, although the understanding of the material, but also just only know fur, text level, writing ability is still in a low level interface. The knowledge is not complete, especially it is very little about professional some departments know knowledge, to write Chinese but not false, sometimes rely on online writing or presentation of ready-made one-sided materials, unwilling to make a deep thinking, put all sorts of things together, the presentation quality is not high, due to the overall quality of their own quality is not high, the leadership of departments can not understand, it is difficult to stand in the perspective A BC D 仔 細(xì) 觀 察 這 張 表 格 , 你 能 得 到 什 么 信 息 ?3個(gè) 點(diǎn) 共 連 : 1+2=3 ( 條 )4個(gè) 點(diǎn) 共 連 : 1+2+3=6 ( 條 )5個(gè) 點(diǎn) 共 連 : 1+2+3+4=10 ( 條 ) 根 據(jù) 規(guī) 律 , 8個(gè) 點(diǎn) 能 連 幾 條 線 段 ?問 題 1 2 3 4 5 6 7能 用 簡 單 方 法計(jì) 算 嗎 ?= 28( 條 )= 8 3 4= (1 7) (2 6) (3 5) 4 根 據(jù) 規(guī) 律 , 你 知 道 15個(gè) 點(diǎn) 能 連 多 少條 線 段 嗎 ?問 題1 2 3 4 5 6+14= 105( 條 ) 15個(gè) 點(diǎn)= 15 7 按 照 簡 單 的 方 法 計(jì) 算 , 你 發(fā) 現(xiàn) 了 什么 , 試 著 歸 納 一 下 。n個(gè) 點(diǎn) 共 連 成 線 段 :1+2+3+4+5+6+( n-1) 再 觀 察 2 3 54點(diǎn) 數(shù) , 增 加 條 數(shù) 和 總 條 數(shù) 之 間 有 什 么聯(lián) 系 嗎 ? 你 還 有 什 么 新 發(fā) 現(xiàn) 嗎 ?可 以 發(fā) 現(xiàn) : 3個(gè) 點(diǎn) 共 連 : 3 2 2=3 ( 條 )4個(gè) 點(diǎn) 共 連 : 4 3 2=6 ( 條 )5個(gè) 點(diǎn) 共 連 : 5 4 2=10 ( 條 )n個(gè) 點(diǎn) 共 連 成 線 段 : n( n-1) 2 n個(gè) 點(diǎn) 共 連 成 線 段 :1+2+3+4+5+6+ +( n-1)n( n-1) 2 今 天 我 們 一 共 有 40個(gè) 同 學(xué) , 每 2位好 朋 友 握 手 1次 , 大 家 一 共 要 握 手多 少 次 ?1+2+3+.+39=( 1 39) 19 20=780( 次 ) 1+2+3+.+39=40 39 2=780( 次 )答 : 40個(gè) 同 學(xué) 一 共 要 握 手 780次 同 學(xué) 們 , 在 我 們 生 活 中 有 許 多 看似 復(fù) 雜 的 問 題 , 我 們 都 可 以 嘗 試 從簡 單 問 題 去 思 考 , 逐 步 找 到 其 中 的規(guī) 律 , 從 而 來 解 決 復(fù) 雜 的 問 題 。 1. 有 幾 條 線 段 ? 2.有 幾 個(gè) 角 ? 321 2198764 53 458 7 61+2+3+4+5+6+7+8=(1+8) 4 =36( 條 ) 9 8 2=36(條 )1+2+3+4+5+6+7=( 1 7) 3+4=28( 個(gè) ) 8 7 2=28(個(gè) ) 三 、 鞏 固 深 化1.觀 察 下 圖 , 想 一 想 。(1)第 7幅 圖 有 多 少 個(gè) 棋 子 ? 第 15幅 圖 呢 ?每 幅 圖 各 有 多少 個(gè) 棋 子 ?1 4 9 16 在 數(shù) 的 過 程 中 , 你 發(fā) 現(xiàn) 了 什 么 ?問 題1 4 9 161 1 2 2 3 3 4 4每 行 的 棋 子 數(shù) 行 數(shù) 棋 子 總 數(shù) 問 題1. 第 7幅 圖 有 多 少 個(gè) 棋 子 ? 第 15幅 圖 呢 ?7 7 49( 個(gè) ) 15 15 225( 個(gè) )2.第 n幅 圖 每 邊 有 多 少 個(gè) 棋 子 ? 一 共 有 多 少 個(gè)棋 子 ?每 行 有 n個(gè) , 有 n行棋 子 總 數(shù) =n2 今 天 你 學(xué) 到 了 什 么 ? 從 簡 單 開 始 , 有 序 思 考用 化 繁 為 簡 , 找 到 規(guī) 律 不足之處,懇請大家給予批評指正 多 邊 形 邊 數(shù) 3 4 5 6內(nèi) 角 和 180 360 540 720( 1) 多 邊 形 內(nèi) 角 和 與 它 的 邊 數(shù) 有 什 么 關(guān) 系 ?( 2) 一 個(gè) 九 邊 形 的 內(nèi) 角 和 是 多 少 度 ?多 邊 形 內(nèi) 角 和 ( 邊 數(shù) -2) 180 ( 9-2) 180 1260 also lack the necessary understanding.Two is the business foundation is not solid, the text level is not high. Their work in the army before, although the understanding of the material, but also just only know fur, text level, writing ability is still in a low level interface. The knowledge is not complete, especially it is very little about professional some departments know knowledge, to write Chinese but not false, sometimes rely on online writing or presentation of ready-made one-sided materials, unwilling to make a deep thinking, put all sorts of things together, the presentation quality is not high, due to the overall quality of their own quality is not high, the leadership of departments can not understand, it is difficult to stand in the perspective 1+2+3+4+5=15( 條 ) 1+2+3+4+5+6+7=28( 條 ) A B A BC A BC D A BC DE 找 規(guī) 律( 1) 3, 9, 11, 17, 20, , , 36, 41, +2 +3 +4 +5( 2) 1, 3, 2, 6, 4, , , 12, , +3 + 3 +3 +3 2 2 2 2 26 309 8 16+6 +6 +6 +6