4下数学：鸡兔同笼 微课精讲

https://v.qq.com/txp/iframe/player.html?vid=l0514lybbjz&width=500&height=375&auto=0

https://v.qq.com/txp/iframe/player.html?vid=m1421y461m1&width=500&height=375&auto=0复制打开网址 www.1ydt.com 下载完整全册word教案试卷及PPT课件点击阅读原文看全部教学内容

https://v.qq.com/txp/iframe/player.html?vid=j05062h9opm&width=500&height=375&auto=0