Arc Builder by Compositive
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For preschools, microschools, and elementary classrooms, age 3 to Grade 5

Plan a whole inquiry arc. You direct, it drafts.

Arc Builder turns your topic, grade, and standards into a multi-week with a lesson plan for every day, built on the Compositive Whole Child Model™. You keep every decision. It does the drafting.

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Currently free for teachers.

Learn about the Compositive Whole Child Model™

See it work

Real arcs. Real lessons. Not a mockup.

Watch the walkthrough, then read excerpts from real arcs and daily lessons made in Arc Builder, preschool through Grade 5.

Grade 3 · 8 weeks

Reflect & Learn

Whose Story Is It? Perspective, Voice, and the People Who Power Our City

Guiding questions

How does a story change when the storyteller changes, and what does that reveal about the people and communities around us?

  • What is point of view, and how does an author choose who tells a story?
  • How does the same event look different depending on who is experiencing it?
  • Who are the people who keep our city running, and what stories do they carry?

+ 2 more in the full excerpt

Grade 3, Common Core aligned, 2026 8-week arc

Age 4 · 4 weeks

Recognize & Act

Community Helpers

A full day: firefighters and fire safety · Week 1, Thursday

Key question: what do firefighters need to do their job?

  • Morning Meeting (20 min): read George and the Firefighters by Margret Rey.
  • Literacy (20 min): talk about what questions the class can ask the firefighter when they come to speak. What is the difference between a question and a comment? Write a list of what the children want to know about being a firefighter.
  • Math (40 min): each child copies their home phone number and address, and 911. Talk about how these are important numbers to know in case of an emergency.

+ 2 more in the full excerpt

Preschool, Colorado pilot, 2026 4-week arc

Grade 2 · 8 weeks

Recognize & Act

The Ocean

How could we clean up an oil spill? · Week 6, Wednesday

Daily big idea: there is more than one way to solve a problem. The class already wrote its shared problem statement: the problem is ___; a good cleanup needs to ___.

  • Literacy (15 min): revisit the 'what we know about the problem' chart and reference images of real cleanup tools: booms that corral oil, skimmers that lift it, sorbents that soak it up.
  • Math (15 min): finalize the fair test. How exactly will we judge which method works better? Count droppers of oil removed, rate the water 1 to 3 for clearness, or compare how clean the feather looks.
  • Inquiry Centers (25 min): each group sketches two cleanup approaches, labels how each is meant to work, and gathers materials from the supply table: cotton balls, sponges, spoons, string, a drop of dish soap, paper towels, mesh.

+ 1 more in the full excerpt

Grade 2, Colorado pilot, 2026 8-week arc
Browse the showcase

How it works

Four steps from a spark to a quarter of teaching.

Your idea is the clay. Arc Builder gives it a first shape, and you keep shaping until it is yours.

  1. 1

    Spark

    Type the topics your class is curious about: dinosaurs, the ocean, community helpers, the math inside music. Arc Builder suggests related sparks as you go.

  2. 2

    Shape

    Pick the grade, the arc length (4 or 8 weeks), and the standards framework. Tell it about your room: class size, day length, the way you like to teach.

  3. 3

    Build

    Arc Builder drafts the whole arc: guiding questions, four capacity phases, a week-by-week calendar, resources, and a performance task. It is a first shape, not a finished thing. Edit anything; rebuild any section with a sentence of feedback.

  4. 4

    Teach, day by day

    Open any day for a full lesson plan across Morning Meeting, Literacy, Math, Inquiry Centers, Enrichment, and Closing Circle. Keep shaping as the arc unfolds: the plan bends to your classroom, not the other way around.

Time

Plan a quarter in an afternoon.

An 8-week arc is 40 school days. Arc Builder drafts the arc first, then each day's plan on demand, so the weekend you would have spent planning goes back to you.

Weeks
4 or 8
Lessons
40
Blocks a day
6

Standards

Coverage you can show your principal.

Choose Common Core or your state framework and every lesson block is tagged with the standards it addresses, alongside the Compositive standards for each domain. Hover any code to read it in plain language.

  • Standards sequenced across the arc, not sprinkled
  • A calendar view of what lands in which week
  • Printable lessons and arc summaries for observations and reviews

Agency

You direct. It drafts.

Arc Builder is an assistant, not a substitute. It writes from your topics, your class, and your teaching preferences, and every section stays editable.

  • Edit any section in place, like a document
  • Rebuild one section with a sentence of feedback
  • Teaching preferences that follow you into every arc

The goal, said plainly: this should save you time. Less of your week drafting, more of it teaching.

Classrooms

A tool for teachers. Not a screen for kids.

Students never log in. Arc Builder plans the day; the lesson day itself is circles, read-alouds, field trips, and hands in the dirt. The only screen it asks for is yours, and only while you plan.

  • No student accounts, no student data, no devices required
  • Plans print cleanly for the clipboard and the sub folder
  • Materials lists built for real rooms: sand, blocks, books, a walk to the mailbox

The framework behind it

Built on the Compositive Whole Child Model™.

Two ideas hold every arc together. Four domains describe the whole child; four capacities describe what children learn to do, in the order an arc moves through them. Hover any label to read what it means.

Domains in color, capacities between them.

Four domains

The whole child, in four parts

Every daily lesson is planned across all four. The literacy block carries , but the morning circle is , the movement break is , and the hard conversation is . Each domain has its own Compositive standards, tagged on every block alongside your academic standards.

A full day: firefighters and fire safety · Week 1, Thursday

Key question: what do firefighters need to do their job?

  • Cognition number recognition
  • Character empathy
  • Health & Well-being fire safety
  • Community Engagement civic duty
How one preschool day is labeled by domain, from a Community Helpers arc in the showcase.

Four capacities

What children learn to do, and the shape of an arc

  1. 1

    Immerse and wonder: observing, questioning, making connections.

  2. 2

    Investigate and act: experiments, expert visits, field trips, research the students choose.

  3. 3

    Connect and care: collaboration, circles, empathy, looking after one another.

  4. 4

    Share and serve: exhibitions, performances, projects that give something back.

Most 8-week arcs open with two weeks of Reflect & Learn, investigate in the middle, keep Care & Connect running throughout, and close with Engage & Serve.

Read about the model on compositive.org

Pedigree

From the people who run the school.

Compositive was founded in 2019 and opened Compositive Primary, an inquiry-based independent school in Aurora, Colorado. Arc Builder grew out of that curriculum work: the capacities, the domains, the standards, and the shape of a school day all come from classrooms that use them.

Your data

Your classroom stays yours.

  • No student data is needed to plan an arc. You describe your class in general terms.
  • Your arcs and lessons are private to you unless you choose to share them.
  • No ads, no data brokers, no tracking pixels on these pages.
Read the plain-language privacy note

Ready to plan your next arc?

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