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问题设计须精当——与吴晶老师商榷 《中小学数学》小学版2011年第1、2期刊登了
一、猜一猜：从1—9这九张卡片里任意取出两张，可以摆出几个不同的两位数？
二、猜一猜：用数字1—9中的任意三个数字，可以组成几个不同的三位数？
就问题一，确定数字1在十位，那么能摆出12、13、14、15、16、17、18、19，计8个不同的两位数；确定另外8个数字分别在十位，又各可以摆出8个不同的两位数，那问题的答案就是8×9＝72（个）
问题二，确定数字1在百位，那有多少个不同的三位数呢？数字不重复，列举如下：
123 124 125 126 127 128 129
132 142 152 162 172 182 192
134 135 136 137 138 139
143 153 163 173 183 193
145 146 147 148 149
154 164 174 184 194
156 157 158 159
165 175 185 195
167 168 169
176 186 196
178 179
187 197
189
198
计2×7＋2×6＋2×5＋2×4＋2×3＋2×2＋2×1＝56（个） 确定另外8个数字分别在百位，又各可以摆出56个不同的三位数，那问题的答案就是56×9＝504（个）
《“搭配中的学问”教学设计》是一篇就人教版小学数学三年级上册第九单元《数学广角》第113页例2教学内容的设计，例2就是用3、7、9三张数字卡片可以摆出多少个不同的三位数， 教材的编排意图是借助操作活动来进一步帮助学生找出排列数或组合数，利用学生已有的知识让学生逐步建构新的知识，帮助学生有序地、不重复不遗漏地找出排列数或组合数，进而初步培养学生有序地思考问题的意识和能力。
该文中还提到，每个问题提出后，
数学问题的设计也须咬文嚼字，问题设计得直白、浅显，激不起学生的学习需求，问题提得苦涩、深奥，容易误导学生，贻害无穷，俗话说“够一够，摘桃子。”依据学生的已有知识水平，设计再上一个台阶的问题，有储备的知识作基础，但还须进一步努力，或独立思考，或合作探究，才更加显得学习是一个知识在螺旋式上升的过程。
理想的には、事前に購読服に年間約前十二から十への結婚式でドレス オーダーヶ月を見て起動する必要があります。これは、あなたが、花を右にアクセサリーを見つけるために変換を実行するのに十分な時間を、髪、服に合わせて提供されます。まだラックブライダルドレスをオフに購入する必要がある、花嫁を変更するためには何らかの仕事を持っているが、彼らが得ることができる6〜9カ月前にウェディングドレスを注文する;約3ヶ月は、部品を変更するには、最初と最後の時間を許可する必要があります。ドレス オーダーもそう今年は望ましいが、3つまたは4つの部品が必要です、長い時間のための特別な必要があるでしょう。花嫁はその衣は失望に到着した場合は、それらに代わるものを見つけるために早めの一年間する必要がありますカラードレス販売、オンライン注文、または事前に愛されドレス腕時計です。
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