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一、诱发估算情趣培养自检能力估算与口算、笔算是相辅相成的。口算和笔算是估算的基础。反过来估算又促进口算和笔算。在加强口算和笔算的同时,结合教材实际适时适量穿插一些适用估算方法的内容,如:1285+5174-2126=?,首先引导学生根据最高位估算,学生容易知道:1千+5千-4千=2千,原式的值在2千左右;然后启发学生根据最低位估算,学生口算得出个位数字必定是3的结果。又如比较21╱41和15╱32的大小,如果采用先通分再比较,便显得繁琐冗长。我们引导学生选择某一适当的标准数作参照再估算,学生通过全面审察,正确选
First, to induce the estimated interest in self-test ability training and calculation, pen and count is complementary. Mouth calculation and pen calculation is the basis for estimation. In turn estimate and promote the port count and pen calculations. In the meantime to strengthen the calculation and pen calculation at the same time, combined with the actual number of appropriate textbooks interspersed with some suitable method of estimating the appropriate content, such as: 1285 +5174-2126 = ?, First guide students based on the highest estimate, students easily know: 1 5000 +4000 Thousand = 2 thousand, the original value of 2 thousand or so; then inspired students based on the lowest estimate, the student mouth count a single digit must be the result of 3. Another example is the size of 21 ╱ 41 and 15 ╱ 32, if you use the first pass and then compare, it becomes cumbersome and lengthy. We guide students to choose a suitable number of standards for reference re-estimation, the students through a comprehensive examination, the correct election