One-straight-cut activities engage middle-school students in learning about symmetry and geometric transformations.

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## Encouraging Students to LOVE MATH with One-Straight-Cut Letters

### Yi-Yin (Winnie) Ko, Connor A. Goodwin, Lauren Ream, and Grace Rebber

## GPS: Composing and Decomposing Shapes Across the Grades

### Kyle Carpenter and Sarah Roller Dyess

Growing Problem Solvers provides four original, related, classroom-ready mathematical tasks, one for each grade band. Together, these tasks illustrate the trajectory of learners' growth as problem solvers across their years of school mathematics.

## Hyperbolic Duckies

### Sophia Wood

Modeling exponential growth with crochet.

## Varying the Intensity of Scaffolding for English Learners

### Haiwen Chu, Jill Neumayer DePiper, and Leslie Hamburger

Vary the intensity of pedagogical scaffolding along three dimensions—grouping, structure, and language—with the same rigorous prompt.

## The Beauty of Regular Hexagons

### Arsalan Wares

The author shares geometry that inspires him.

## Problems to Ponder

### Chris Harrow and Justin Johns

Problems to Ponder provides 28 varying, classroom-ready mathematics problems that collectively span PK–12, arranged in the order of the grade level. Answers to the problems are available online. Individuals are encouraged to submit a problem or a collection of problems directly to mtlt@nctm.org. If published, the authors of problems will be acknowledged.

## Construct It! Progressively Precise: Three Levels of Geometric Constructions

### Carmen Petrick Smith

This article shares an activity scaffolding the construction of the circumcenter of a triangle, culminating with a Triangle-Ball Championship game.

## Construct It! Triangle Puzzle Challenges

### Enrique Ortiz

This article presents an original puzzle that supports students’ development of visual thinking and geometry ideas based on the Van Hiele levels of geometric thought.

## Imagine It! Choose Your Own Pattern Block Adventure

### Anita A. Wager, Brittany Caldwell, and Jamie Vescio

When given the opportunity to play with mathematical materials and ideas, children demonstrate their mathematical understanding in innovative ways.

## The Do Nothing Machine

### Keith Dreiling

The Trammel of Archimedes traces an ellipse as the machine’s lever is rotated. Specific measurements of the machine are used to compare the machine’s actions on GeoGebra with the graph of the ellipse and an ellipse formed by the string method.