With our mortar mixtures all dried it was time to test the strength of our walls.  Did we make a good choice with our mortar mixture?  We wanted our walls to be strong enough to keep the bunny out of our garden!

Each pair of first graders tested the strength of their walls by using a wrecking ball.  The higher the wrecking ball was released from, the more force that was used against the wall.  The whole class recorded which angle the wall last stood with.   Each pair's hope was that their wall could withstand the force behind the largest angle with the most force!  As engineers we built our walls and as scientists we tested them.  

First graders first thought about the rocks they brought in to build their walls.  Some rocks were different colors, shapes, and sizes.  Each of these factors would affect the structure of their walls they designed.  We practiced classifying the rocks into different groups.

Then, with their rocks and mortar mixtures in hand, first graders were eager to begin designing their walls.  Spreading their mortar mixture atop and around the rocks they collected, walls were being erected left and right.

Thanks to everyone  who collected rocks!  We had many different shapes, sizes, colors, and textures, just like Yi Min found for her wall.  

First graders are making mixtures of their own and comparing one mixture to the next with graphs.  These mixtures were all made with man-made materials.  Next steps...mixtures with earth materials!!!