Disequilibrium is Piaget’s term to describe when what a learner already knows comes into conflict with new information. Learners must…

# What’s in a name?

This post is by reader and strings enthusiast Laura Bofferding, Assistant Professor, Purdue University I was first introduced to number…

# (Re)Thinking Context

A recent conversation between two New York City math educators, Carol Mosesson-Teig and Kara Imm Kara, I have been thinking…

# Tricky Teens

Now that we’re moving into spring, I wanted to be sure my kindergarteners were beginning to gain a foundation for place…

# Moving straight ahead

Those of you who are fans of the middle school curriculum Connected Math Project (CMP) will especially appreciate this string.…

# Encouraging Strings Discussions

Defining the Problem: In a recent workshop, a third grade teacher shared the following: “I think I’m doing it right,…

# Dot Talk: Early Numeracy

This post is from Raquel Goya, a Kindergarten teacher at Hoover Elementary in Palo Alto, CA. Raquel noted that, “Although…

# New percentage number strings

We recently saw the problem above on a New York CCSS-M 6th grade benchmark test. A few teachers I was…

# Searching for Friendly Numbers

Students who are working to become efficient with fractions must learn to seek out “friendly” numbers — a shifting target…

# “Stack of Bills” string

Here’s a string I designed with a team of fifth grade teachers who were looking for creative ways to encourage…

# Fractions as Operators (Dot Arrays)

Here’s a collection of strings written by teacher participants at the Summer Institute at Math in the City (City College,…

# From additive to multiplicative thinking

A few weeks ago our colleague and collaborator Pam Weber Harris led a really interesting numeracy workshop at Math in…

# The “King of Strings” teaches us that strings are maatwerk

I recently reached out to Willem Uittenbogaard. Willem was one of the original collaborators between Math in the City (founded by…

# Challenge problems, helper problems

When designing strings, there are typically one or more helper problems before a challenge problem. For example, you might start…

# Subtraction string – where is the answer?

My name is Jennifer DiBrienza. I taught elementary school in New York City public schools for 9 years and began…

# Arrays on the West Side

We recently learned that the third grade team at Manhattan School for Children (Elizabeth Frankel-Rivera, Madelene Geswaldo, Alice Hsu and…