🌿 Grass under coloured light: the whole packet

🌿 Grass under coloured light · 4th–8th grade · 14 days of testing · about $3 · 20 minutes a sitting

My days, if the fair is 18 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 the colour of the light the grass gets, then how tall the grass grows in 14 days will ________________, because _____________________________________________

What I think will happen, in my own words:

4 levels × 3 tries at each = 12 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🌾 Grass seed
• 🥤 Paper cups with a hole poked in the bottom: 12
• 🪴 Potting soil
• 🚰 Water from the tap
• 🥄 Measuring spoons
• 🟥 See-through coloured cellophane: red, blue and green
• 🎞️ Clear plastic wrap: for the clear covers
• ✂️ Kid scissors
• 🩹 Tape
• 📏 A ruler

Be safe: 🧼 Wash your hands after

1. Fill twelve cups with soil and sprinkle a teaspoon of grass seed on each.
2. Cover the seed with a thin layer of soil and give each cup two tablespoons of water.
3. Cut sheets of red, blue and green cellophane and clear plastic wrap, twice as tall as a cup.
4. Wrap three cups in red tubes, three in blue, three in green and three in clear, and tape them.
5. Tape a piece of the same colour over each tube's top, so all its light comes through the colour.
6. Stand all twelve cups on the same sunny windowsill.
7. Every other day, lift each top and give every cup two tablespoons of water.
8. On day 14, measure the tallest blade in each cup in millimetres.
9. Write down how green and thick each cup looks, too.
10. Find the mean height for each colour and draw a bar graph.
11. Wash your hands after touching the soil.

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

I changed: Cover   I measured: how tall the grass grows in 14 days (mm)

MY GRAPH (a bar graph: cover along the bottom, mm 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: put a second set of all four colours on a shady shelf, and graph sunny and shady side by side.

1. What made you want to ask this question? Say something like: I wanted to know: does grass grow best under red, blue or green light?
2. What did you think would happen, and why? Say something like: I thought changing the colour of the light the grass gets would change how tall the grass grows in 14 days, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed the colour of the light the grass gets (Clear, Red, Blue, Green) and measured how tall the grass grows in 14 days in mm.
4. What did you keep the same, and why does that matter? Say something like: I kept the same grass seed, a teaspoon in each cup and two tablespoons of water every other day the same, so only the colour of the light the grass gets was different.
5. How many times did you test it? Say something like: 3 times at each of my 4 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: Clear and Green 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: put a second set of all four colours on a shady shelf, and graph sunny and shady side by side.