山东省历下数学九年级：九年级数学下册教学工作总结

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所在地区：山东省历下区
认证名称：历下数学九年级
认证号码：LXSXJNJ
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简介：
本公众号服务于济南市历下区九年级的学生和家长,借助区优秀的教师资源,让学生学习数

历下数学九年级的内容如下:

1. 整数的加减法运算

– 整数加减法的一般式:a + b = c,a – b = c,a + b – c = 2a

– 整数加减法的运算律:a + (b + c) = (a + b) + c,a – (b + c) = (a – b) + c,a + (b – c) = (a + b) – c

– 整数减法的运算律:a – b = (a – b) + 2,a – b – (c – d) = (a – b) – (c – d),(a – b) – c = a – b – c + 2

– 整数加法的运算律:a + b = (a + b) + 2,a + b – (c – d) = (a + b) – (c – d),(a + b) – c = a + b – c + 2

2. 分数的加减法运算

– 分数加减法的一般式:a/b + c/d = (a + c)/b = (a + d)/b = 2a/b

– 分数加减法的运算律:a/b + (c/d) = (a + c)/b,(a/b) + (c/d) = (a + c)/b,(a/b) + (c/d) + e = (a + c)/b + e

– 分数减法的运算律:a/b – (c/d) = (a – c)/b,(a/b) – (c/d) = (a – c)/b,(a/b) – (c/d) + e = (a – c)/b + e

3. 小数的加减法运算

– 小数加减法的一般式:a/b + c/d = e,a/b – c/d = f,a/b + c/d + e = g

– 小数加减法的运算律:a/b + (c/d) = (a + c)/d,(a/b) + (c/d) = (a + c)/d,(a/b) + (c/d) + e = (a + c)/d + e

– 小数减法的运算律:a/b – (c/d) = (a – c)/d,(a/b) – (c/d) = (a – c)/d,(a/b) – (c/d) + e = (a – c)/d + e