The materials that schools choose for their classrooms matter more than almost any other decision district leaders make every year.

Yet a recent Gallup poll reveals that while education leaders recognize the value of a strong curriculum, many struggle to identify or even define it. That struggle extends to the classroom, where only 30 percent of teachers feel fully prepared to teach multilingual learners.

Consider the landscape: California alone is home to more than one million multilingual learners, and they comprise about 19 percent of total enrollment in the state’s public schools. In many districts, that number climbs to 30, 40, even 50 percent.

These students bring a wide variety of strengths to classrooms. Many are bilingual — or on their way — a cognitive advantage that enhances problem-solving, creativity, and academic achievement. So what’s the best way to unlock their full potential while raising the bar for everyone?

The answer requires getting serious about curriculum.

English Learners Success Forum (ELSF) is a national nonprofit I founded over nine years ago that works alongside school districts to support informed decisions about the materials they adopt and implement. From this work, ELSF has created “Materials Must-Haves” — three most essential, non-negotiable features that must be intentionally included for instructional materials to respond to the needs of multilingual learners and bolster success for all students.

At the center is a core premise: effective instructional materials must intentionally integrate language and content learning. The Must-Haves help make that integration visible within materials. Yet, these Must-Haves are not the full picture of quality, nor do they include all the features that make materials inclusive of multilingual learners. Instead, they identify what is most often missing, inconsistent, or underdeveloped in current materials.

While ELSF’s more comprehensive “Guidelines for Improving Instructional Materials for Multilingual Learners” and “Benchmarks of Quality” remain central to defining what truly effective instructional materials look like, the Must-Haves represent a more concrete, practical expression of that vision, offering educators, leaders, and publishers a way to recognize three of the most essential features that reflect how language and content integration should appear in instructional materials.

California recently released its list of state-approved math curricula, so it’s a great time to highlight the three Must-Haves for Math Materials, where language demands are often more invisible and more neglected.

Must-Have #1: Mapping math and language development For years, education has treated math as if understanding fractions or solving equations doesn’t require sophisticated language skills. Yet any teacher who’s watched a multilingual learner struggle to explain their mathematical thinking — even when they clearly understand the concept — knows this is false.

Instructional materials need to make explicit connections between mathematical concepts and the disciplinary language required to engage with those concepts. This means curriculum that doesn’t just teach “area and perimeter” but intentionally builds the vocabulary and sentence structures students need to compare, contrast, justify, and prove their reasoning.

Strong materials map how language demands grow alongside math concepts across grade levels by moving students from everyday language (“the answer is bigger”) to precise academic expression (“the sum is greater than”). The best curricula also support all four modes of communication: speaking, listening, reading, and writing. This doesn’t just improve classroom participation; it also has a positive impact on college readiness and students’ ability to see themselves as mathematicians.

Must-Have #2: Monitoring math and language development Once materials map language and content development, educators need tools to monitor whether students are making progress on both fronts. This is where many curricula fall short.

Typical math assessments focus almost exclusively on whether students got the right answer. But educators also need to know: Can students explain their reasoning? Are they using mathematical language with increasing precision?

Curricula should equip teachers to assess both mathematical reasoning and academic language through tasks that ask students to explain their thinking, clear success criteria that address both content and language, and actionable “look-fors” to track growth and adjust instruction.

In practice, this looks very different from traditional worksheets. Instead of 20 computation problems, imagine students solving three problems, then writing or verbally explaining their strategy, comparing approaches with a peer, and identifying which method is more efficient. Students aren’t just learning math or learning English: they are learning to do mathematics along with the language to effectively express themselves. This is essential for all students but especially multilingual learners.

Must-Have #3: Making connections through collaboration and conversation For decades, education has conceived of math as a solitary activity, but mathematical thinking — posing problems, debating approaches, building on others’ ideas — is fundamentally social.

Mathematicians do not work in isolation, and neither should any student, but especially multilingual learners.

Research shows that structured peer interaction accelerates both language acquisition and conceptual understanding. But this isn’t about occasional group work or a “turn and talk” thrown in sporadically. Strong materials build in sustained, structured routines for mathematical discourse, including student talk prompts that push beyond surface-level sharing, peer activities that require justification and peer feedback, and sentence frames that give multilingual learners access to mathematical conversations while they’re still building English proficiency.

The key phrase is “built-in.” If the curriculum treats student collaboration as an add-on or enrichment activity, it won’t deliver results. The best materials make structured mathematical discourse a core part of every unit, every week.

Common pitfalls to avoid As leaders review materials, ELSF recommends watching out for these red flags:

Superficial language supports. Glossaries and vocabulary lists are helpful, but they’re not enough. If language instruction feels like an afterthought — something separate from the math content — it likely won’t serve multilingual learners well.

Translation without transformation. Some curricula simply translate materials into Spanish or other languages without adapting the instructional approach. True multilingual materials leverage students’ home languages as cognitive assets, not just compliance measures.

Collaboration without structure. Random group work isn’t the same as thoughtfully designed mathematical discourse. Look for specific protocols, talk moves, and facilitation guidance for teachers.

The curriculum that districts choose either opens doors or closes them. The research is out there, and the frameworks are available. What’s needed now are district leaders willing to prioritize multilingual learners from the onset of making adoption decisions — and these Must-Haves provide the clarity to do it.

Because when we get this right for multilingual learners, we get it right for everyone.

Crystal Gonzales is the Executive Director of the English Learners Success Forum where she collaborates with national experts, organizations, educators and content developers to increase the supply of quality K-12 instructional materials that meet the needs of the growing EL population.