*By William McCallum*

On March 20, 2015, I received the following email:

Thank you for submitting your proposals to the K–12 OER Collaborative. We are pleased to advise you that Illustrative Mathematics has been selected as a vendor to create a rapid prototype unit for the following grade band and subject: 6–8 Mathematics.

With that e-mail, we were off and running in the most exciting race of my professional career. We later agreed to deliver a pilot-ready version of grades 6–8 for the 2016–17 school year, rolling out units just in time as the year progressed, and delivered a final version in the summer of 2017, along with aligned professional learning. I’m glad that it was only later, after we had delivered the curriculum, that we discovered this should have been impossible.

With the introduction of the Common Core State Standards in 2010, most states had agreed on what students should know and be able to do at each grade level for the first time in the history of education in the US. This allowed publishers to produce curricula that were both standards-aligned and coherent—curricula that truly told the story of mathematics across grade levels. We founded Illustrative Mathematics to help curriculum and assessment writers do that, but five years later we decided there was room for a contribution that our talented team of educators and mathematicians was uniquely positioned to make—a contribution that was faithful to the progressions and connections in the standards, incorporated what we know from years of research about effective instructional modes, and was practical and educative for teachers in real classrooms.

Encouraged by the enthusiastic reception of IM 6–8 Math, and by the top reviews from EdReports, we hardly paused to take a breath before starting work on our high school curriculum and integrated professional learning. In 2019, we released Algebra 1 (with a complete set of supporting lessons for underprepared students), Geometry, and Algebra 2.

And then we launched into our most ambitious undertaking of all: six grades of elementary curriculum. IM K–5 Math required new thinking in many ways. Teachers in K–5 are usually generalists, teaching many subjects, so thinking how to support them is different. Also, students in K–5 are not necessarily reading in early grades, so activities have to be designed for verbal or visual communication of the task, with corresponding guidance for teachers. We created new instructional routines (e.g. Act it Out for kindergarten), new teacher supports (e.g. reflection questions on pedagogy, math content, student thinking, and beliefs and positioning), and new structures for supporting student learning (e.g. centers). We pioneered a new set of supports for culturally responsive teaching. We couldn’t have done any of this without an awesome team of writers who truly embraced the IM way of balancing attention to the mathematics with attention to student thinking. You can learn more about the curriculum by watching some of the webinars here. With IM K–5 Math we have achieved our trifecta!

For me, achieving a complete, coherent, standards-aligned curriculum K–12 is a dream come true, a dream that realizes the promise of common standards. And yet, just as common standards by themselves were necessary but not sufficient to change the course of mathematics education, so curriculum is, in the end, just another beachhead in the struggle to create a world where all learners know, use, and enjoy mathematics. A classroom which truly exemplifies that vision is a classroom where not only are students using IM K–12 Math, but where teachers are implementing the problem-based instructional model and districts are supporting those teachers with planning time, collaboration time, and aligned assessments. IM K–12 Math is both a monumental achievement and a mere beginning. Stay tuned for more!

### Next Steps

Learn more about IM K–5 Math by watching our free, on-demand webinars. Topics include:

- Why Choose IM K–5 Math?
- Comparing IM K–5 Math and IM 6–12 Math — What’s New?
- IM K–5 Math as a Support for Culturally Responsive Pedagogy
- Advancing English Learners in IM K–5 Math

##### William McCallum

Bill McCallum, founder of Illustrative Mathematics, is a University Distinguished Professor of Mathematics at the University of Arizona. He has worked in both mathematics research, in the area of number theory and arithmetical algebraic geometry, and mathematics education, writing textbooks and advising researchers and policy makers. He is a founding member of the Harvard Calculus Consortium and lead author of its college algebra and multivariable calculus texts. In 2009–2010 he was one of the lead writers for the Common Core State Standards in Mathematics. He holds a Ph. D. in Mathematics from Harvard University and a B.Sc. from the University of New South Wales.