These cards are the cards that I created to use with my 4th grade students to move them from the concrete level of natural resources to the abstract level of the concept. I usually have the students sort actual items before using these cards and then we move to these pictorial cards as the students understanding progresses. We usually let the students sort the cards 2-3 times. Each time the students discuss what properties they used to sort the cards by and the reasons that they used to justify their answers. After a quick discussions and presentation from each group, the students resort the cards and again must explain and justify their reasoning. The process continues until student groups are able to show an ability to not only sort the resources appropriately but also justify their thinking based on the various properties that they used to sort the cards.