Walk Through the Exercise From a Blank Page

The short answer: Every exercise can have the walkthrough students wish existed: the given, each legal step, and the check, drawn and narrated as a polished video. Golpo builds that from the exercise, the solution, or the script you already trust.

Why this is practical now: Golpo makes a workbook-scale set practical. It plans the sequence, draws each intermediate result, narrates it in the course voice, syncs the reveal, and returns a video you can still repair frame by frame.

A teacher's selfie and voice can lead the whole set, so a long problem list still feels like one instructor. The Golpo API can generate the next walkthrough as soon as the solution is ready.

Use the full Golpo production system

Golpo is built to be the world's best AI whiteboard explainer video maker. Give it a topic, a prompt, a script, an audio recording, or a source document. It scripts, plans the scenes, designs the visuals, narrates, times and synchronizes every frame, and returns a polished video. One person can run that system across a whole course.

For walkthroughs, keep every legal step on the whiteboard. The instructor's own audio or voice clone can explain the reasoning, while frame-by-frame editing repairs a sign, unit, or label without replacing good work.

• Start with an idea or source. Golpo can draft the script and plan the scenes from a topic, a document, or your outline. Script Mode can also speak the exact words you already trust.
• Keep the creator present. With AI Presenter, a course creator, founder, professor, or YouTuber can upload a selfie and appear beside the whiteboard. One person can lead a large lesson library without recording every visual sequence on camera.
• Use the right voice. Own Narration turns uploaded or live-recorded audio into the visual lesson. An authorized Voice Clone gives recurring lessons a recognizable voice at scale. Consent and pronunciation review remain required.
• Repair instead of restarting. The frame-by-frame editor can replace text, images, references, or an individual visual when the QA pass finds a local problem.
• Automate at scale. The Golpo API can be called from Codex, Claude Code, or through the Golpo MCP server in Cursor, VS Code with GitHub Copilot, Claude Code, Claude Desktop, and Visual Studio. The course platform can generate, poll, review, and publish without a person moving files between tools.

Blank page versus submitted error

The wrong-step spoke quotes a learner’s line and breaks it. This page has no learner line. The first frame is the problem statement and empty space. The practice spoke pauses before the answer. A walkthrough may be assigned after that pause, as the revealed path, and it should be labeled as the full solution so it does not pretend to be the try. How an equation is typed in Markdown or LaTeX is the equation guide. This page assumes the expression is already the course’s expression and teaches the solution order.

The walkthrough contract

1. Restate the given. Base and height, or the expression as printed. Units if the problem has units. Nothing extra.
2. One legal step. The narration says the rule it is applying: “area of a triangle is half the base times the height,” or “multiplication happens before addition.”
3. Write the result of that step. Intermediate numbers are spoken. A jump from the given to the final answer fails the draft even when the answer is right.
4. Check against a second representation. The triangle’s surrounding rectangle, or the parenthesized form of the expression. The check is in the script, not only in the instructor’s head.
5. Stop. The next exercise is the next video. A montage of six problems is a worksheet, and a worksheet’s check is too easy to skip.

The creator agent drafts from the key and must include the intermediate lines the key used. The QA agent solves from the stem alone. If the agent’s path is legal and different, the instructor decides which path the course teaches. The video then teaches that one path. Silent disagreement between two legal paths is how a course ends up with a picture of one method and a narration of another.

The triangle

Constructed problem: base 10, height 6. Triangle area is (base × height) / 2 = (10 × 6) / 2 = 60 / 2 = 30. The surrounding rectangle is 10 × 6 = 60. Half of 60 is 30. The two pictures have to agree. A frame that shades the whole rectangle and calls it 30 fails. A frame that uses 10 × 6 without halving, and labels the triangle 60, fails. The QA agent computes both 30s. Equality of those two paths is the release condition.

The operation order

Constructed expression: 2 + 3 × 4. Multiplication first: 3 × 4 = 12. Then 12 + 2 = 14. The left-to-right trap yields (2 + 3) × 4 = 20, which is the value of a different expression. The lesson should show 20 only as the parenthesized expression, clearly marked. If the pictures label 20 as the value of the original line, the watch-back fails.

Both exercises are small on purpose. A walkthrough of a page-long proof can exist, and it will need a longer approved script and a longer timing value than the one-minute pilots on this page. The contract does not change: given, legal step, intermediate, check, stop. The hub still blocks the render until that check agrees.

Own Narration: OFF · Script Mode: ON · Duration: 1 minute · Orientation: Horizontal (16:9) · Style: Dry Erase · Color: ON · Language: English · Voice: Male 2 · Pace: Normal · Music: None

Start from a blank page. The triangle has base ten and height six. Area equals base times height, divided by two. Ten times six is sixty. Sixty divided by two is thirty. The area is thirty. Use the surrounding rectangle as the check. A rectangle with the same base and height has area ten times six, which is sixty. The triangle is half of that rectangle, and half of sixty is thirty. The two paths agree. If a later step says the area is sixty, that answer belongs to the rectangle, not the triangle. Show the formula, the product, the half, and the rectangle, in that order. The walkthrough starts with no student ink on the page, and the last mark is the check. Thirty has to appear twice, once from each path. The triangle and the rectangle have to share the frame at the end.

A blank page. Triangle base ten, height six, area thirty. The rectangle around it is sixty, and half of sixty is thirty. End with the triangle and the rectangle sharing the frame, both pointing at thirty. Allowed labels: Base 10; Height 6; (10 x 6) / 2 = 30; Rectangle 10 x 6 = 60; Half of 60 = 30. Do not add a sample stamp, a demo label, or any claim that the lesson is fictional. Show only the labels listed. If a number appears, it must match the narration exactly. No extra dates, prices, percentages, logos, or quotations.

Walk through from a blank page. Pause before the half.

Own Narration: OFF · Script Mode: ON · Duration: 1 minute · Orientation: Horizontal (16:9) · Style: Dry Erase · Color: ON · Language: English · Voice: Female 1 · Pace: Normal · Music: None

Start again from a blank page. Compute two plus three times four. Multiplication happens before addition. Three times four is twelve. Twelve plus two is fourteen. The value is fourteen, not twenty. The twenty comes from a different expression. Two plus three, in parentheses, times four. Two plus three is five. Five times four is twenty. The parentheses change the order, so they change the result. Fourteen and twenty are both correct answers to different questions. Show the multiplication first, then the addition, then the parenthesized line beside it. Circle the multiplication before you touch the two. Then do the parenthesized line as its own problem. A learner who adds first is answering the second expression. Point at the operation the page actually asked for. Fourteen answers the first expression. Twenty answers only the line with parentheses. Keep both results, and label which expression each one belongs to.

Blank page. Three times four is twelve, plus two is fourteen. The parenthesized line is twenty. End with both results labeled by their expression. Allowed labels: 2 + 3 x 4 = 14; 3 x 4 = 12; 12 + 2 = 14; (2 + 3) x 4 = 20. Do not add a sample stamp, a demo label, or any claim that the lesson is fictional. Show only the labels listed. If a number appears, it must match the narration exactly. No extra dates, prices, percentages, logos, or quotations.

Order of operations. Keep fourteen and twenty distinct.

Review

• The opening frame contains the problem and no answer.
• Each spoken step is legal for the course’s stated rules. This course’s arithmetic lesson uses conventional order of operations.
• The triangle’s 30 matches half of 60. The expression’s 14 matches 12 + 2. The parenthesized 20 is labeled as a different expression.
• No learner’s name, score, or “common mistake” statistic is invented. The left-to-right path can be shown as a different expression without a fake percentage of students who do it.

Risks

Walkthroughs feel finished because they end on the right answer. The failure mode is a skipped constraint: dividing by a quantity that might be zero, dropping a unit, or halving a triangle whose height is not the perpendicular height. The QA agent should be instructed to list assumptions. For these two pilots the assumptions are simple: the height is perpendicular to the base, and the expression uses standard precedence. A later exercise with a non-perpendicular side needs a different script, not a reused triangle.

Rendering is fast enough that a course will be tempted to walk through every answer in the back of the book. That volume is a reason for a stricter key check, not a reason to skip it. One unchecked video assigned to a cohort teaches the error at the size of the cohort.

How the solution is labeled so it stays a solution

Learners should know, before they press play, that the blanks are about to be filled. The page title can be the problem. The button can say “Watch the worked solution.” A button that says “Try it” on a video that opens with the answer is the practice spoke wearing the wrong name. The platform stores that label in the lesson record. The QA agent’s text check looks for the opening sentence of the script. If the script begins with “the area is 30” before the base and height have been restated, the draft fails even though 30 is correct. Order is part of correctness for this product.

A second representation is required because a single arithmetic path can hide a misread given. For the triangle, base 10 and height 6 are restated, the half-product is 30, and the rectangle is 60. Imagine a constructed mis-draft that treats 10 as the height and 6 as the base and still multiplies to 60 before halving. The product matches, so a careless check passes, and the picture may still show the height along the wrong side. The watch-back therefore includes the orientation: the 10 is the horizontal side the course called the base, and the 6 is the perpendicular height. The QA agent cannot see the picture. The person at watch-back can. Both gates stay.

Operation order needs the same double path. The script computes 3 × 4 first and lands on 14. It also writes the parentheses that produce 20 and names them as a different expression. A course that assigns this video beside a homework set should not include a problem whose convention differs, such as a historical notation or a programming language where the same glyphs do something else, without saying the convention. The pinned convention for this lesson is standard arithmetic precedence. A programming course that wants integer division or a different associativity writes a different lesson and pairs it with a test, on the programming spoke. Reusing the “14” file inside a Python unit because the glyphs look familiar will eventually teach the wrong evaluation order for that language.

Volume is the remaining operational rule. If the workbook has forty exercises, the course picks the exercises that introduce a new legal move. The others can remain text solutions that a person checked. Filming all forty because rendering is fast creates forty watch-backs. Skipping the watch-backs creates forty ways to ship a swapped label. The instructor who wants every answer in video form has accepted forty reviews. The queue should show that cost before the generate calls go out.

Captions and on-screen algebra have to match the spoken steps, because some learners will read and not listen. For the triangle, the caption sequence is base 10, height 6, product 60, half is 30. For the expression, the caption sequence is 3 × 4 = 12, then 12 + 2 = 14, with (2 + 3) × 4 = 20 kept in its own caption so a reader skimming the frame list cannot merge them. The QA agent compares caption text to the script when the platform extracts captions. If captions are burned in by the render, watch-back is the comparison. A caption that says “area equals 60” on the triangle frame is a release block even when a later frame repairs it. Learners pause on the wrong frame. The repair they never reach does not undo the frame they copied into their notes.

Automate it: review gates and publishing with the Golpo API

For exercise walkthroughs, the whole path from source to published lesson can run as one pipeline on the course platform. An agent in Codex with the Golpo Codex Skill, in Claude Code with the Golpo Claude Skill, or in Cursor, VS Code with GitHub Copilot, Claude Code, Claude Desktop, or Visual Studio through the Golpo MCP server can call the Golpo API, wait for the render, and hand the file to the platform's review steps. Production stops being the limit on how many checked lessons a course can offer.

1. Attach the reference first. Store the exercise and its full worked solution with the lesson before any script is drafted.
2. Review the script against the reference before rendering. If a solution or source exists, the platform's QA agent checks the draft against it: it re-solves, re-adds, or re-reads, then compares. A mismatch or an uncertain result stops the job before Golpo renders anything.
3. Generate with Golpo. The agent sends the approved script in Script Mode, with the course's locked style, voice, Video Instructions, and Voice Instructions.
4. Transcribe what was actually said. Run speech-to-text on the finished video's audio. Learners hear the transcript, not the draft.
5. Run two independent transcript reviews. Make two separate LLM calls, separate from the creator agent and the QA agent. Each gets only the transcript and the reference, with no access to the draft or to the other reviewer's verdict. Each checks every spoken number, term, and claim, then returns pass or fail and quotes the line it objects to. The lesson moves on only when both pass. A failure or a disagreement goes to an instructor.
6. Check the frames. Pull a frame every few seconds and confirm every number and label on screen matches the approved script.
7. Publish. The pipeline posts the video to the course platform or LMS through its API as a draft, then releases it under the course's own approval rule.

FAQ

Can these lessons be generated and published automatically?

Yes, on the course platform's side. Using the Golpo MCP server or the Golpo Claude Skill, a pipeline can check the script against the exercise and its full worked solution, generate the video, run two independent transcript reviews, and post the lesson to the platform as a draft. Anything that fails a check goes to an instructor.

How is this different from explaining a wrong step?

This video starts from the problem. The wrong-step video starts from a line a learner submitted. If the learner’s line is on screen, you are on the other page.

What is the triangle’s area?

Base 10 and height 6 give (10 × 6) / 2 = 30. The rectangle around it is 60, and half of 60 is 30. Both paths are required in the check.

Why is 2 + 3 × 4 equal to 14?

Because 3 × 4 is 12, and 12 + 2 is 14. The expression (2 + 3) × 4 equals 20 and has to be labeled as that different expression.

Can the video pause for a try?

It can, and then it is sharing a duty with the practice spoke. Label the pause so learners know a full solution follows. Do not call a complete walkthrough a quiz.

Who produces the second solution?

The platform’s QA agent, from the stem, not from the draft. Golpo renders only after that solution matches the path the course decided to teach.

What if two legal methods both work?

An instructor picks the path this lesson teaches. The video shows that path. The other path can be a later video with its own check. The pictures and the narration have to describe the same path.

Where do equation fonts and LaTeX entry live?

In the Markdown and LaTeX equation guide. This page is the teaching sequence once the expression is already the expression the course meant.

Related guides

• Checked lesson videos — do not assign the walkthrough before the second solution agrees.
• The learner’s wrong step — start from their line.
• Lesson plus practice — the try that can come before this reveal.
• Markdown and LaTeX equations — how the expression is entered.
• Textbook companions — when the exercise has a book number and a printed key.

Start from the blank problem, show each legal step, and end on a check that a second solution can reproduce.