By the Illustrative Mathematics team
When members of the Illustrative Mathematics team recently spent a day inside two co-located schools in District 11 of New York City Public Schools (NYCPS), we expected to see solid instruction.
What we experienced went further than that.
We saw classrooms where students were actively making sense of mathematics, teachers were skillfully orchestrating discussion, and learning felt purposeful and coherent across grade levels.
The schools—P.S. 567, Linden Tree Elementary School, and M.S. 127, The Castle Hill Middle School—offer a close-up view of what high-quality instructional materials paired with strong implementation can look like in practice. Together, they help explain why District 11’s gains are showing up across the system.
A Day in District 11 Classrooms
Across both schools, the IM team observed math instruction in first, third, sixth, and seventh grades. In every classroom, students were doing real mathematical work. They explained their thinking, built on one another’s ideas, and engaged in productive struggle with support from teachers who clearly knew both the content and their students well.
What stood out most was coherence. Instructional routines, expectations, and mathematical habits felt aligned across grade levels. Students were accustomed to talking about math, not just completing it. Teachers used the curriculum thoughtfully and consistently, creating space for student thinking while maintaining rigor.
That classroom experience is reflected in the data.
Linden Tree Elementary School: Rapid Growth Through Coherent Instruction
P.S. 567, Linden Tree Elementary School, began using IM Math in the fall of 2023. The decision was intentional.
School leaders were seeking stronger alignment with NYCPS Mathematical Shifts, including real-world connections, collaborative problem-solving, and deeper conceptual understanding. While their previous curriculum was hands-on, it did not consistently support those shifts. IM Math was selected because its core design intentionally embeds these instructional moves while aligning closely with NYC Solves and district priorities.
The impact on students has been significant:
- 2023: 26.3% proficient
- 2024: 33.8% proficient
- 2025: 47.8% proficient
This represents a 21.5-point gain over three years.
During our visit, that growth was visible. Students in early grades confidently shared observations and strategies. Teachers used common routines to establish a shared sense of safety and access, while still pressing for understanding. The result is a more coherent, conceptually rich math experience for Linden Tree students.
Castle Hill Middle School: Building Strong Instructional Systems Over Time
At M.S. 127, The Castle Hill Middle School, improvement has been driven by a deliberate, system-level approach.
As a Targeted Support and Improvement school, leaders conducted a comprehensive evaluation of departmental needs and identified a clear priority: adopting a curriculum that fosters active student engagement through structured discussion, collaboration, and critical thinking. IM Math met that need.
Adoption was paired with intentional instructional and staffing decisions, including:
- Hiring an assistant principal with a background in mathematics
- Teaching the curriculum with fidelity for a full year to build department-wide coherence before thoughtfully adapting instruction to meet students’ needs
- Adding an additional math coach to support teachers and model effective instructional practice
- Strengthening integrated co-teaching classrooms by hiring special education teachers with strong math content knowledge and placing highly effective teachers in those settings
- Partnering with Teaching Lab to continuously reflect on and refine instructional practice
The results show steady progress:
- 2022: 27.2% proficient
- 2023: 39.6% proficient
- 2024: 36.1% proficient
- 2025: 41.5% proficient
This represents a 14.3-point gain over four years, with proficiency figures excluding eighth-grade Algebra students.
In classrooms we observed, students tackled challenging problems, justified their reasoning, and engaged deeply with one another’s ideas. Teachers were clearly working from a shared vision of what strong math instruction looks like.
What These District 11 Schools Show Us
The experiences of Linden Tree and Castle Hill help explain the broader success District 11 is seeing across NYCPS. From 2022 to 2025,* the district achieved a 24.8-percentage-point gain in math proficiency across grades three through eight. That kind of growth does not come from quick fixes.
These schools show that high-quality instructional materials are an essential ingredient, but they matter most when paired with strong, sustained implementation. IM Math provides a coherent, problem-based curriculum that supports deep learning. When districts maintain long-term attention to instruction, staffing, and professional learning, the curriculum can truly take hold in classrooms.
Students gain consistent opportunities to reason and make sense of mathematics year after year. Teachers benefit from being supported as professionals doing complex intellectual work.
Why This Matters for NYCPS and NYC Solves
What we saw at Linden Tree and Castle Hill helps illustrate why District 11 has been able to build momentum ahead of—and alongside—NYC Solves. The initiative is designed to bring coherence, strong instructional materials, and aligned practice across NYCPS. These two schools show what that vision looks like on the ground.
Maintaining and strengthening NYC Solves is essential to extending this kind of success across the system. When schools commit to high-quality instructional materials and invest in sustained implementation, students gain confidence, understanding, and access to meaningful mathematics.
Linden Tree and Castle Hill underscore that systemwide change begins in classrooms—and that, with the right conditions in place, those classroom experiences can add up to lasting impact across NYCPS.
Our time at Linden Tree and Castle Hill offered a powerful reminder that sustained improvement in mathematics is not the result of unique circumstances or short-term initiatives. With a clear instructional vision and long-term commitment, schools throughout large urban districts and beyond can create learning environments where students belong in mathematics and are supported to succeed.
*Note on assessment context:New York State updated its mathematics assessments beginning in 2023, with changes phased in over multiple years. These updates should be taken into account when interpreting proficiency trends across time. Despite these changes, District 11’s post-2023 data show sustained improvement across grades and student groups.
Next Steps
To learn more about Illustrative Mathematics and our commitment to high-quality, coherent math instruction that supports teachers and students over time, visit illustrativemathematics.org or schedule a call with the IM team.
