Number Strings

This is a re-post from the Global Math Department Newsletter from 12/2/14

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Anyway, number strings are a classroom routine which I believe need to be highlighted more than they are currently. Rachel Lambert, an author of the number strings blog, was my school’s math consultant when I began my career. She has helped to shape who I am as a math teacher and my beliefs of what good math education is.  The following is an article from the GMD newsletter published on 12/2/14:

You may be aware of the Contexts for Learning Mathematics curriculum developed by Cathy Fosnot. A major component of the curriculum is a pedagogical technique designed to introduce and practice computational ideas and strategies called number strings. You may not be as aware of how to utilize this particular technique in your classroom. That’s where Rachel Lambert and Kara Imm’s blog called Number Strings comes to the rescue!

“Kara and I started talking about where we kept the number strings we wrote every day as classroom teachers: bulging file folders, assorted post-it notes, a massive notebook,” recalls Lambert about the inspiration for the blog. “What was the digital equivalent, we wondered? Could we make a website that collected number strings and shared them freely with teachers? That was our initial inspiration for the site. We started to look for information on the web about number strings and found that many sources were misinformed about number strings, and so we wanted to provide clear guidance for teachers.”


A number string is a short, focused computational routine in which kids share multiple strategies that are represented by the teacher. There is a focus on the development of flexible strategies for computation and big mathematical ideas. “Many of the number strings on the site are written to solve the current problems that teachers have, particularly with places in which the Common Core expectations don’t match with available curriculum.” Lambert answers as to how classroom teachers can use the site.

If you’re wondering how “number strings” differ from “number talks” you can find out here. “Teachers as designers,” Imm and Lambert stress, is the goal for writing the blog. “That’s what we want to restore to teachers — the idea that teaching is a creative, generative, imaginative act. This is very different for teachers who feel like teaching is implementing someone else’s ideas, in a kind of scripted manner. Especially in a time of heightened pressure to prepare for tests, this designing aspect of teaching is really important.”

1 thought on “Number Strings

  1. Pingback: Procedural Fluency in a Problem-Based Classroom | When Math Happens

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