Below are some general tips and suggestions to assist with the management of materials for the Earth’s Changing Surface Unit:
Although the river tables in Lesson 3 are easy to assemble, several teachers pointed out that they were not very sturdy during the actual exploration and would bend inward due to the weight of the sand and water.
To prevent this from occurring with your students, make sure that you elevate the entire surface the river table is resting upon, not just the river table, during the exploration. When you simulate slope, place the books or wood blocks used under the legs of the table or desk the river table is setting upon, not under the river table itself. See illustration below for details:

Several teachers noted that the 25 cm (10 in) plastic tubing for the students’ volcano setups was not long enough in length. To ensure that this length of tubing is adequate for the setups, make sure to cut the hole in the top of each box approximately 7.5 cm (3 in) from the open end of the box (see preparation step #2 on page 223 of the Teacher Lesson Manual). This distance was specified so that a 25 cm (10 in) piece of plastic tubing would be adequate for the exploration.
