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Common Core ELA4th GradeReading: Informational

RI.4.3: Explain What Happened and Why

Also written as CCSS.ELA-LITERACY.RI.4.3 · Cluster: Key Ideas and Details.

All 43 4th Grade ELA Standards

The Official Wording

Explain events, procedures, ideas, or concepts in a historical, scientific, or technical text, including what happened and why, based on specific information in the text.

Common Core State Standards, Grade 4, Reading: Informational Text · Read it at the source · Checked October 14, 2026

What RI.4.3 Means in Plain English

Fourth graders explain how something happened or works in a history, science or how-to text, and why, using the facts the text gives. Reading about maple syrup, they say why farmers tap trees only in late winter and why forty gallons of sap boil down to one.

Third grade (RI.3.3) described how events or steps connect, using words like first, then and because. Fourth grade wants the explanation itself, built from specific details. Fifth grade (RI.5.3) looks at how two or more people, events or ideas interact.

RI.4.3 I Can Statements

  • I can explain the steps of a process in a science text.
  • I can explain what happened and why, using facts from the text.
  • I can tell why each step matters, not just its order.

RI.4.3 Worked Example

A how-it’s-made passage where every step has a reason, and the weak answer lists the steps without giving a single one.

Read the Story
Maple syrup begins as sap, a watery liquid that flows inside sugar maple trees. Farmers can collect it for only a few weeks, at the end of winter.The sap runs best when nights are below freezing and days are above it. Each freeze and thaw builds up pressure inside the tree, and the pressure pushes sap out of any opening.A farmer drills a small hole in the trunk and taps in a spout. Sap drips into a bucket or flows through plastic tubing to the sugarhouse.Fresh sap is about 98 parts water and only 2 parts sugar, so it tastes like faintly sweet water. The farmer boils it for hours in a wide, flat pan. The water rises away as steam, and the sugar stays behind.It takes about 40 gallons of sap to make one gallon of syrup.
A short passage written for this page.
Question: Why do farmers boil the sap for hours, and why does it take about 40 gallons of sap to make one gallon of syrup?
Not Yet“First they drill a hole, then they collect the sap, then they boil it, and then it turns into syrup.”Every step is in the right order, but the question asked why. The answer never mentions water, steam or how little sugar the sap holds.
Meets the Standard“Sap is about 98 parts water and only 2 parts sugar. Boiling turns the water into steam that rises away, and the sugar stays behind. It takes hours because there is so much water to get rid of. That is also why you need about 40 gallons of sap: almost all of it is water that leaves as steam, and what is left is about one gallon of thick, sweet syrup.”Both parts of the answer grow from one specific fact, how much water the sap holds, and the student connects that fact to each result.
Question Stems to Use
What happened, and why did it happen?Why does this step come before that one?Which fact in the text explains this?What would happen if they skipped this step?How does this part work, in your own words?

Common Mistakes with RI.4.3

Listing steps without reasons

“First they drill, then they collect, then they boil.”

Try this: Add “because” after every step and have students finish the sentence with a fact from the text, not a guess.

Explaining from what they already know

“They boil it to kill the germs.”

Try this: Ask “Where does the text say that?” and send students back to find the sentence that actually explains the step.

Skipping the hardest idea

An answer that never mentions the freeze and thaw, the one part that explains why the season is so short

Try this: Have students draw the tree at night and during the day, with arrows, before they write about why sap runs only in late winter.

Where RI.4.3 Fits

Comes BeforeRI.3.3Describe how events, ideas or steps connect, using time, sequence and cause words.
AlongsideRI.4.5Describe how a text is organized, such as in time order or as cause and effect.W.4.2Write to explain a topic clearly, with facts, definitions, details and linking words.
Comes NextRI.5.3Explain how two or more people, events, ideas or concepts in a text connect and interact.

Practice RI.4.3

Quick Check

  1. Why does sap flow best at the end of winter?
  2. What happens to the water in the sap when the farmer boils it?
  3. Why does it take about 40 gallons of sap to make one gallon of syrup?

RI.4.3: Other Names

RI.4.3CCSS.ELA-LITERACY.RI.4.3

Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved. Official wording from the Common Core State Standards PDFs at corestandards.org, last checked October 14, 2026. The explanation, I can statements, example, mistakes and practice on this page are EMStudio’s own, written beside the official wording. They are not part of the standard.