🪣 Filtering muddy water: the whole packet

🪣 Filtering muddy water · 4th–8th grade · 1 day of testing · about $2 · 50 minutes a sitting

My days, if the fair is 14 days away

Count back from your fair day and write in each date. Fewer days than this? The jobs share days, in this order; nothing is skipped.

Dates from my teacher

• My question is due
• Testing starts
• My results table and graph are due
• My board is due

In this packet

1. 🗓️ My project plan
2. 💭 My hypothesis
3. 🧺 Change, measure, keep the same
4. 🪜 My steps
5. 📊 My results
6. 📓 My logbook
7. ✅ My conclusion
8. ✂️ Board titles to cut out
9. 🏅 The judge's questions and my certificate

If I change what the filter is made of, then how many lines of print you can read through the filtered water will ________________, because _____________________________________________

What I think will happen, in my own words:

3 levels × 3 tries at each = 9 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🟫 Soil dug from the garden or yard: 3 tablespoons
• 🚰 Water from the tap: about 6 cups
• 🏖️ Sand (from a sandbox, or play sand): about 3 cups
• 🪨 Small pebbles or gravel, rinsed: about 3 cups
• ☁️ Cotton balls: about 12
• 🥤 Paper cups with a hole poked in the bottom: 3
• 🥛 Clear plastic cups, all the same size: 3
• 🥛 A measuring cup
• 🥄 Measuring spoons
• 🥄 A spoon
• 📄 Paper
• 🖍️ Crayons or markers

Be safe: 👶 Small parts · 🧼 Wash your hands after · 💧 Water · 🧽 A bit messy

1. Print the word SEE on ten lines of a sheet of paper, making it a bit smaller on each line.
2. Stir 3 tablespoons of garden soil into 4 cups of tap water to make muddy water.
3. Never drink the muddy water, or any water that has been through a filter.
4. Rest a paper cup with a hole in its bottom on top of a clear cup.
5. Fill the paper cup halfway with sand, gravel or cotton balls: one kind for each filter.
6. Stir the muddy water, then pour half a cup slowly through the filter.
7. Wait until it stops dripping. That can take a few minutes.
8. Stand the clear cup on your sheet and look straight down through the water.
9. Count the lines of SEE you can still read, and write the number in your table.
10. Rinse the sand and gravel, use new cotton balls, and test each filter two more times.
11. Wash your hands after touching the soil.
12. Find the mean for each filter, and draw a bar graph.

Write each number in your results table the moment you measure it.

I changed: Filter   I measured: how many lines of print you can read through the filtered water (lines read, of 10)

MY GRAPH (a bar graph: filter along the bottom, lines read, of 10 up the side)

What I noticed: ______________________________________________

Write something every day you work on it, even the days you only gather things. More days? The three-page logbook prints from peabody.kids/science-fair/templates/logbook.

My hypothesis was ☐ right ☐ partly right ☐ not right.

I know because my numbers show:

What surprised me, or what might have gone wrong (7th and up):

Next time I would test:

Idea: Change a second thing: stack two layers, sand on top of gravel and then gravel on top of sand, and compare the lines read.

1. What made you want to ask this question? Say something like: I wanted to know: which filter makes muddy water clearest?
2. What did you think would happen, and why? Say something like: I thought changing what the filter is made of would change how many lines of print you can read through the filtered water, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed what the filter is made of (Sand, Gravel, Cotton balls) and measured how many lines of print you can read through the filtered water in lines read, of 10.
4. What did you keep the same, and why does that matter? Say something like: I kept the same muddy water, stirred before every pour and the same amount of filter, filling the cup halfway the same, so only what the filter is made of was different.
5. How many times did you test it? Say something like: 3 times at each of my 3 levels, and I found the middle number.
6. What did you find out? Show me in your numbers. Say something like: Look at my table: Sand and Cotton balls gave different numbers, and here's the pattern.
7. Was your hypothesis right? How do you know? Say something like: My numbers show whether I was right, partly right or not, and I can show you where.
8. Did anything go wrong, or surprise you? Say something like: One try was odd, so I did it again and wrote it in my logbook.
9. If you did it again, what would you change or test next? Say something like: I'd change a second thing: stack two layers, sand on top of gravel and then gravel on top of sand, and compare the lines read.