我推荐美国60年代的课本

Grade 1-12 都可以从下面

https://raysarithmetic.wordpress.com/rays-free-arithmetic/

喜欢的也可以去买

Rays Arithmetic Series (8 Volume Set) Reprint Edition

by Ray Joseph (Author), Ruth Beechick (Author), Mott Media (Author)

by echodrawing

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把楼主两个帖子拼一起存下来。谢谢推荐。 感谢楼主既有专业知识又愿意分享。

RoseLeigh 发表于 2020-12-10 12:28

Mark