Sands of the World
Lesson 3 of 6
Objective: SWBAT observe sand samples and then find the possible origins of the sand on a world map by plotting the latitude and longitude.
Materials / Setup:
In order to complete the lesson, you will need the following materials:
- Small sand samples from around the world (1/4 cup of sand is more then enough. I posted a request to my Facebook friends and immediately received responses from 14 different cities and countries!)
- Metric ruler
- Petri dishes
- Large world map for class (or a world map projected)
- Hand lenses
- Scotch tape
- Data sheet
- 3x5 index cards
Once you obtain your sand samples, you need to look up the approximate latitude and longitude for each sample and make a note of it. Assign a random letter of the alphabet to each team of students. The number of teams should correspond to the number of different sand samples you have. (Teams of two would be ideal.)
Day 1: Engage
I start the lesson by playing the Sand Art video as students enter the room. You will be amazed by how quiet they enter and how entranced they become by watching this beautiful piece of art become alive right in front of their eyes. (Save this link for one of those days when the students are a little "squirrely"; you'll thank me later!)
After watching, I ask the students what type of "medium" (material) was used to create the beautiful pictures they just viewed. Students are really impressed to realize that the entire masterpiece was created using nothing but sand!
I ask the kids why they think I had them watch the video. Most of them will instantly connect the idea of sand to the beach, and then connect the idea of the beach to the ocean! I explain that sand is a very important part of the ocean, as it not only forms the ocean floor, but also helps to store minerals and nutrients and serve as a home and a source of protection for many of the ocean's inhabitants.
I ask the students if they have ever considered where sand comes from. After all, it didn't just appear! I also ask them of they think that all sand is the same, no matter what ocean, beach, desert, or part of the world it comes from. I accept a few volunteer responses and then tell then that we will have the opportunity to learn more about the origins of sand during today's lesson.
Day 1: Explore
Next, I place students into groups of 2-3 and provide each team of students with a 3x5 index card. The students will fold the card in half, lengthwise, and cut a V-shaped notch in the middle of the fold so a diamond hole in the middle results when the card is unfolded. Students then stick a piece of scotch tape across the hole and turn the card so the sticky side is facing up.
I hold up several sand samples (stored in small plastic baggies) and explain that each one has come from a mystery location somewhere on Earth. I pass out one sample to each group and have the students sprinkle a small handful on the sticky side of their index card. Next, I have them write the designated letter from their sample on the card. (I have students create two cards just like this in case they need an additional sample.) After the cards are made, I collect the baggies so that the sand does not get accidentally spilled or mixed.
After creating their sample card, I list the following observation criteria on the board and have each team compile data for their sand sample, observing using a hand lens and microscope, and recording data on the following:
- Color: Students record the most obvious color, as well as any other colors of the sand grains in their sample
- Length: Student will estimate the length of the smaller and larger sand grains; computing the average size in mm. (*Advanced students can compute a nearly exact length using a microscope and computing based on the scale representation.)
- Shape: Round, oval, square, rectangular, triangular?
- Rounding: Are the corners sharp or rounded?
- Surface Texture: smooth or rough?
- Materials: Do you notice small pieces of rocks, crystals, shells? What else?
- Magnetism: Is there a large, medium or small amount of material attracted to a magnet?
- Students will then place a drop of dilute vinegar on each sample and see if any grains fizz. They can use their hand lens to note which grains react with the acid.
- Miscellaneous: What other qualitative data do you observe as you investigate your sample?
Day 2: Explain
After students have studies their sand sample and recorded their observations, it it time for them to learn more about the sand sources and beaches around the world. In order to lean more, I have created a Sand Sources Web List for students to visit. They read through each site on the web list, comparing their sand samples to the information provided. It will be the student's responsibility to take notes and conduct additional online research, as necessary, to confirm the origin of their sand. Students will work together using the provided web list, their observations and their own research to try to determine the location their sand may have come from.
Once students believe they have a definitive origin for their sand, they will come to be to get their answer confirmed by providing me with the approximate latitude and longitude their sand came from.
If they are correct, I let them know. If not, I provide a few small hints, such as the hemisphere, continent, or a range of latitude or longitude positions to help them narrow down their search. Students can then research within those parameters. I allow students three attempts at finding the origin of their sand.
Days 2 and 3: Elaborate
Once students believe they have narrowed down their sand's origin to 3 or fewer locations, they collaborate with groups who made observations similar to theirs. This time, they help each other observe and research again, with the goal of determining slight differences in their sand that may lead them to a more definitive origin.
Once students feel confident in the origin of their sand, they will present me with their findings and explain their thinking, based on the evidence they have collected. They provide me the approximate latitude/longitude positions that describe where their sand originated. If students have correctly determined the region their sand came from, they are done!
If not, I provide them clues to aid in their search, such as the correct hemisphere, continent, or a range of latitude/longitude positions. I allow each group of students three attempts at finding their sand's origin. If they cannot, they have to explain to me what observations or research led them astray and how this information could apply to sand in a different region.
If time permits, I also like to show the 2013 documentary, Sand Wars, which discusses the shortage of sand due to human endeavors, such as mining and building. While it is not directly related to the lesson, it is a great way to open student's eyes about the negative effects of human activity on sand, and not just ocean water or animals.
Day 3: Evaluate
At the end of the lesson, I pass out blank paper and have students respond to several reflection questions (below) in writing. Students are evaluated on their understanding by the clarity and thoroughness of their responses.
- Where did your sand originate? What clues helped you to figure this out? What clues made it harder to solve the mystery?
- Describe the environment where your sand came from. How does the environment match the attributes of your sand?
- Which characteristics were most useful in identifying the unknown sample?
- Are there any noticeable global patterns of distribution of sand by color? Explain.
- Are there any noticeable global patterns of distribution of sand by any other features? Explain.
- How can the origin of this unknown sample be determined by comparing it to the team data?
- What other kinds of data (that we did not collect in our study) might also be helpful?
- Which beach or region might you most like to visit, based on the quality of the sand?
To learn about a great resource that can be used to supplement this lesson, please watch my video below!