I ring my chime to get the class’s attention and ask them to return to the carpet squares and ‘Show Five’. Once seated, I announce that we are about to begin the third Science lesson in our unit about the effects of the sun. To engage the students, I often start the lesson by accessing prior knowledge and connect past lessons to current material.
“Who remembers when we observed the garden?” “I do!” “We noticed that all plants needed..” “Sun!” “And...” “Shade?” “Some do need less sun, but what else does every living thing need?” We learned about this with our Life Science units, so this was a great time to remind them. “Water?” “Exactly! We talked about a plant’s need for water." "How do we know how much to water it?" "Let's study the effect that sun plays in this equation!” Simple steps like this are fine to introduce new ideas that connect with prior lessons because it makes the material in a recognizable and accessible. When this step is complete, we are ready to move on.
For this lesson, I introduce a brief video clip that illustrates how the process of evaporation works in a backyard and show it to the class. I chose this clip because it’s a really cute way to deliver instruction on an important concept. While the video does include a brief demonstration of a different experiment delivered in a whole group setting, I choose to conduct a more interactive version because- with this class- it’s easier to have the students work in pairs. Always feel free to adjust the delivery to meet the needs of your individual class.
As we watch, I stop to note the parts where important vocabulary and explanations are highlighted, while keeping in mind to connect it to our work in the garden to better access prior knowledge. “Remember in our last lessons, we learned about ways nature provides shade for the plants that need it?” “Yep!” “We’re going to talk a little bit about the effect sun has on the irrigation of a garden..that means how a plant gets water. What do you think are some ways?” “Rain?” “That’s one way. Any other ideas?” “A water hose?” “That’s another great way. Gardeners design ways to irrigate the plants to make sure they are taken care of in the best way possible.”
“The effect of the sun is something that gardeners have to think about. Any idea why?” “To make sure it has enough sun.” “Yep, enough water too. The sun is an essential can’t live without it part of a plant’s life. But we saw in the garden that too much sun can be bad, right? One reason is because sun like we saw in the video causes evaporation. This can cause the plant to lose water and it won’t have enough to live. We’re going to conduct an experiment today to measure places around the school where the sun causes the most evaporation. Why do we need to know this?” “So we know where plants will grow best!” This line of Q & A helps lead them through the concept in a way that increases effective processing and engages them in a real world way.
• Small Jars (baby food jars work great!)
As a form of assessment, I go over the steps without the complete details. As the project develops, this will tell me who comprehends the concept from the video and who needs additional support. I take a minute to explain the process they will follow to observe about the effect of sun on water:
• First, take a small jar. Add add water until it’s half full (baby food jars work great!).
• Next, put a lid loosely on the jar to better mimic a natural environment.
• After, use tape to mark the level of water. Label the jar with the location.
• Then, put the jars in several places around the room and school that experience different levels of sun. Leave them for a few hours (we began this experiment in the morning to allow maximum time).
• Last, check the water levels to see what areas experienced the most water loss. Record your answers.
Before we begin the first steps, I go over some additional review and instruction to give the lesson valuable context. “Who can tell why it’s important to know the best places for plants?” “Because they need sun and water!” “Who can tell me why?” “Some plants need more water. They need a place where they can get it.” “Right…so when we learn places where the sun evaporates more water, we need to make sure those plants get water, right?” “Right, it’s like our animals!” “Exactly like our animals! We are creating a healthy habitat for..” “Our plants!”
While, this seems like a daunting concept to tackle with this age, it’s an important one. We’ve learned about appropriate habitats in our various units. Learning the effects of the sun on a plant’s water supply is essential to supporting healthy plant life, so the more they know about it, the better they can transfer to other of their lives. In the bigger picture, it helps address ways the help areas (like mine!) that are subject to seasonal droughts, reinforcing the concept that we are stewards of the Earth.
At the end of lunch, we collect our jars from the various locations. After we all gather on the carpet squares, we bring each jar one at a time up to measure the amount of evaporation. To give this step a valuable visual, we line up the jars on a table in the order of most evaporation to least. I note this order of locations on a chart. "Who has an idea on why some jars have less water than others?" "Because some were in hotter places." "Why would this make a difference?" "The hotter places made the water evaporate so there wasn't as much left." "Exactly! That's why we need to really pay attention to the locations of all living things to make sure that the environment will provide them what they need to be successful."
“What did you notice about the places where there was more evaporation?” “The places on the playground has less water.” “That’s a great observation of the effect of sun on water. Any ideas why this happens?" "Because there's more hot places there?" "Right. Sunny places have more…” "Sun!" "And sun causes more..." “Evaporation!” This step is short by design because my intent of the lesson is to give the students an opportunity to recognize the effect that sun has of the amount of water in our environment. I again rang the chime and asked the students to stand up and stretch upward, just like evaporation. Movement like this gives the lesson context..and is fun too!