how to build a slat and paper grader
Evaporate water to form salt crystals.
The color black absorbs all frequencies of visible light, which helps the light energize the water molecules which evaporate when they get hot. It is important that the pan is somewhere warm, because the water will evaporate into the air more quickly. As the water evaporates, the salt doesn’t leave with it! Therefore, the concentration of salt in the water left behind increases. Eventually, the concentration gets so high that the water becomes supersaturated, and the salt will begin to recrystallize into a solid. When all of the water is gone, you will have salt!
Have every assignment count equally, instead of weighting tests to be equal to 50% of students’ overall grades, homework as 25%, and so on. This will save you massive amounts of time at the end of the quarter.
In the past, I’ve set aside certain times of the day to grade papers, such as during students’ Morning Work, while the kids used math centers or completed cooperative projects (and therefore were being pretty independent), or right after dismissal. Every day during the predetermined time, I tackled whatever papers the kids had created since the day before. This was a very effective way to make sure that papers never piled up, and was manageable because my students completed most of their written work in workbooks and journals which are not graded.
Invest Your Time Earlier in the Process
- Clearly explain the criteria you will use when evaluating student papers. Writing out your criteria insures consistency and provides a useful point of discussion in student conferences.
- If possible, provide a model to students, by photocopying an A paper from a previous assignment, for example. Explain why the paper is successful.
- Discuss the assignment: go over it sentence by sentence; clarify important terms; reword; illustrate with examples or ask students to do this.
- Include informal writing about the assignment before the final paper is due (see “In-class Writing Activities” for suggestions).
- Conference with students: If time, see each student individually to help them develop and revise their paper. Make your key contribution here; put a grade and only minimal comments on the final paper.
- Use peer review (see “Using Peer Review”)
The stack of papers on your desk seems bottomless, and mid-way through the paper you are reading, you cannot remember what the student is arguing. Now you have to go back and re-read the paper. On top of this, you are not even sure what constitutes a good and bad paper anymore.
A suggested method is to use five containers that are all the same size and shape. Put the same amount of water into each container. Use the first container as your control, and do not add any salt to it. Add 1 teaspoon of salt to the second container, two teaspoons to the third container, and so on.
You could make a science fair project out of this concept by measuring different amounts of salt into a specific amount of water and testing how well different objects float.
As with many art supplies, there are two main categories of watercolor paper: artist quality and student grade. While sometimes it pays to spring for artist quality materials, I’ve found student grade watercolor paper often works great.
Watercolor paper comes in both heavy and light varieties. Heavy paper can absorb more water and is often more expensive. I buy paper in the 90-140lb range for my students and have them tape it to their drawing boards.
Watercolor paper also comes in a variety of textures. Hot press paper has a smooth, hard surface while cold press paper has semi-bumpy or rough texture. The majority of watercolor artists prefer cold press. There is also a rough paper I seldom use but is wonderful for pure washes.
Watercolor paint is made with a pigment that is then mixed with a binder. Binders are what hold the pigment together. Different types of paint use different types of binders. Watercolor paints are more vibrant and transparent because watercolor has fewer fillers and the binder, which is usually gum Arabic, is absorbed by the paper. Therefore more color can show on the surface of the paper or board.