If you teach 4th grade reading, you've watched the exact same scene play out a hundred times. A student reads a passage. They answer the Part A multiple-choice question — main idea, theme, central message — and they get it right. Then they look at Part B, which says "Which sentence from the passage best supports your answer to Part A?" — and they pick a sentence that doesn't actually support anything.
That's the moment most reading-comprehension tutors give up and say "they don't understand it." But the issue isn't understanding the passage. It's understanding the two-step.
What state tests are actually asking
Part A / Part B (sometimes called "evidence-based selected response") is the dominant format on PARCC, Smarter Balanced, FSA, STAAR, and most state tests that succeeded them. Roughly 60-80% of reading items on a 4th grade test follow this pattern.
The intent is good: tests want to know not just whether students can pick the right answer, but whether they can defend it. A student who picks the right Part A by lucky guess and a wrong Part B isn't really demonstrating comprehension.
The unintended consequence: students who understand the passage but don't understand the FORMAT lose points they shouldn't lose.
The specific failure mode
When I started watching my own 4th graders work through Part A / Part B, I noticed the wrong-Part-B picks fell into one of three patterns:
Pattern 1: They picked the most memorable sentence. A passage about honeybees ends with "A creature smaller than a thumbtack can communicate where to find food without making a sound." It's a beautiful sentence. It's also the strongest evidence for the main idea. But many students will instead pick the sentence about waggle-dance figure-eights — because that's what they remember as "cool."
Pattern 2: They picked the FIRST sentence about the topic. Whatever was introduced first in the passage. They assume "first = important = evidence."
Pattern 3: They picked a sentence that's TRUE but doesn't support the specific Part A claim. This is the most common one. The passage says lots of true things. Part A is asking about ONE of them. Part B requires matching the evidence to that specific claim.
The teaching move that fixes it
The fix isn't more practice. It's making the two-step explicit.
Here's the script I use with my own students:
> Step 1: Read Part A. Decide on your answer. Cover up Part B before you look at it. > Step 2: Write down (in the margin, on scratch, anywhere) the EXACT WORDS from the passage that prove your Part A answer is right. You should be able to point to them. > Step 3: NOW look at the Part B choices. Find the one that matches what you wrote down.
That's it. The whole trick is forcing the student to predict the evidence before they see the multiple-choice options. The wrong-answer choices in Part B are designed to look plausible to students who skip the prediction step. Once a student commits to evidence first, the wrong choices look obviously wrong.
I taught this script to a small intervention group three years ago. Their Part B accuracy went from about 45% to about 80% in two weeks. Same kids, same passages, no new content. Just the script.
Where students still get stuck
Two stumbling blocks come up even after the script works:
The "two answers seem right" problem. Sometimes two Part B choices both support the Part A answer. The tip-off here: state tests almost always prefer the BROADER restatement-style evidence over a specific detail. "The narrator realized that being patient was harder than she expected" beats "She sat down on the rock and sighed." Both support the same Part A theme, but the broader sentence is the better evidence.
The "evidence isn't a single sentence" problem. Sometimes the best evidence is actually two sentences working together, and the test asks you to pick TWO. Students who haven't seen the "select two" instruction often pick one and move on. Teach them to actually read the instruction line every time.
Practice with the right format
I built a 4-passage Part A / Part B practice set for 4th grade that targets these specific patterns. It's the format students will see on the test — original passages (2 informational, 2 literary), Part A / Part B for each, plus a short writing prompt that uses the same evidence-citing skill.
What's inside:
- Passage 1: "The Honeybee Waggle Dance" (informational) — main idea + supporting evidence + inference
- Passage 2: "Building the Brooklyn Bridge" (informational) — central idea + two-evidence Part B + inference
- Passage 3: "The Lost Compass" (literary) — theme + evidence + author's purpose
- Passage 4: "Marcus and the Math Test" (literary) — theme + evidence + figurative-language inference
- Short writing prompt with 4-point rubric
- Complete answer key with explanations for every question
Standards: RI.4.1, RI.4.2, RL.4.1, RL.4.2, W.4.9. Single classroom license.
What this practice gets you
If you spend two weeks teaching the script and using this packet for daily warm-ups before the test, you'll see Part B accuracy go up. Not because the kids are smarter. Because they finally understand what the question is actually asking them to do.
That's the difference between a kid who reads well and a kid who tests well. Both matter. Part A / Part B is where they intersect.