This 5-page 5th grade photosynthesis sheet is built on Jan Baptist van Helmont's willow tree experiment. Students read how a 2.3 kg tree and 90.7 kg of dried soil changed over five years, then subtract to find that the tree gained 74.4 kg while the soil lost 0.1 kg. Part 2 adds a short note on what scientists know today, a four-label diagram and a claim, evidence and reasoning frame. It fits NGSS 5-LS1-1, and page 5 is the answer key.
5-LS1-1
“Support an argument that plants get the materials they need for growth chiefly from air and water.”
Questions 1 to 3 and the claim, evidence and reasoning frame in item 5 ask students to argue from the mass data that the soil did not supply most of the tree's mass.
A three-paragraph reading with a photo of a potted willow. It gives the starting masses of the tree (2.3 kg) and the dried soil (90.7 kg) and the masses after five years (76.7 kg and 90.6 kg).
A two-row table of starting and ending masses. Students subtract in two boxes to find the tree's gain and the soil's loss, then write whether the tree got most of its mass from the soil.
A short box explains that van Helmont credited water, while today's science points to carbon dioxide from the air. Students then label four numbered pointers on a plant diagram from a word bank.
Students fill two blanks in the claim, write two facts with numbers from the table as evidence, and use four lines to explain how photosynthesis uses carbon dioxide and water to build the plant.
Worked subtraction for items 1 and 2, the diagram labels and a model claim, evidence and reasoning.
Predict first
Before students read, ask whether a tree gets its mass from soil. Many say yes, which makes the 0.1 kg soil loss in the table land harder.
Teach the frame
Use item 5 as an early claim, evidence and reasoning task. Have students underline the two numbers they plan to use before they write.
Check the subtraction
Questions 1 and 2 are decimal subtraction with 76.7 and 90.6. Circulate there first, because a slip in either answer breaks the evidence in item 5.
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