Sidewalk Stones
For more information see the Mathematics Assessment Project site http://map.mathshell.org/tasks.php?unit=HE13&collection=9&redir=1
![](https://www.google.com/images/icons/product/drive-32.png)
For more information see the Mathematics Assessment Project site http://map.mathshell.org/tasks.php?unit=HE13&collection=9&redir=1