The elective adventure for Webelos and Arrows of Light, Adventures in Science has been retired but it's still a good opportunity to learn about science. One activity is to have the Cub Scouts draw a scientific fair test. Make it easy for them with the Cows Mooing Softly acronym. Read all about it, and get your FREE printable!
An experiment is a “fair test” to compare possible explanations. Draw a picture of a fair test that shows what you need to do to test a fertilizer’s effects on plant growth.
The handbook explains independent, dependent, and control variables. But I have trouble remembering the difference between independent and dependent variables.
I found a super fun way to remember which is which! It's called Cows Mooing Softly. 🙂
The C stands for Change. What is the one thing that you'll change in your experiment?
The M stands for Measure. What will you measure in your experiment?
The S stands for Same. What will stay the same in your experiment?
Having a “cow” to remind the Scouts will help them as they're drawing their fair test.
What is a Fair Test?
Start by having a discussion about what a fair test is. The Webelos handbook gives a great example using medicine. If someone is sick and you give them three medicines, you won't know which one makes them better. Instead, you need to give them only one medicine at a time.
For our fertilizer experiment, ask the Scouts how plants grow. Make sure they mention that they start as seeds, and we plant them in soil. They need warm temperatures, water, and sunlight to grow.
As the plant grows, we can measure how fast it grows. We can count how many seeds sprouted by counting the number of shoots. We can also measure how tall the plant grows.
Talk to the Scouts about what fertilizer is. Basically, fertilizer contains several chemical elements that plants use as nutrition. These chemicals are typically found in soil, but there may not be enough to grow strong plants. Fertilizer adds these chemicals to the soil so that plant is well nourished.
Ask the Scouts what they think will happen if you put fertilizer on one plant but not on another.
Draw a Fair Test
The Scouts can simply draw out this experiment, or they can make it a comic strip as the handbook suggests.
To continue with the Cows Mooing Softly theme, I've created a fun printable that they can use for their drawings. Just enter your email below, and I'll send it to you. This will subscribe you to my (mostly) weekly emails. If they aren't helpful, feel free to unsubscribe at any time.
Draw a Fair Test
They're fourth and fifth graders, so I'm sure you'll hear, “We don't know what to draw!” Here are some suggestions to share with them.
What Will Change
What Will Stay the Same
Watering Can or Cup (representing water)
Sun (representing sunlight)
Thermometer (representing temperatures)
What You'll Measure
Calendar or Clock (representing how quickly the plants sprout)
Tick marks or Hash Marks (representing how many sprouts you grow)
Ruler (representing how tall the sprouts grow)
I hope this printable is helpful and your experiment goes well!
Yours in Scouting,