You might be confused about the Common Core, but this fourth grader isn't. Watch Savanna Burris of Meadow Homes Elementary in Concord, California breaks down the "box method" of multiplication — in ...
当前正在显示可能无法访问的结果。
隐藏无法访问的结果当前正在显示可能无法访问的结果。
隐藏无法访问的结果