Thank you for your interest in NCTMâ€™s Illuminations. Beginning in mid-April, all Illuminations content will be moving to nctm.org/illuminations. Interactives will remain openly available and NCTM members will have access to all Illuminations lessons with new filtering and search options. We hope you will continue to utilize and enjoy these resources on nctm.org.

## Search Results

### 5.1.1 Playing Fraction Tracks

3-5
Think about how fractions are related to a unit whole, compare fractional parts of a whole, and find equivalent fractions.

### 5.1.2 The Role of the Teacher

3-5
Two video clips illustrate communication about mathematics among a teacher and her students.

### 5.1.3 Communication among Students

3-5
Use communication as a tool to deepen their understanding of mathematics.

### 5.1.4 Reflecting on Practice

3-5
The teacher reflects on her own mathematical learning.

### 5.2.1 Distance, Speed, and Time Relationships Using Simulation Software

3-5
Use a software to simulate two runners along a track.

### 5.3.1 Exploring Properties of Rectangles and Parallelograms Using Dynamic Software

3-5
Explore geometric relationships and make and test conjectures.

### 6.1.1 Learning about Multiplication Using Dynamic Sketches of an Area Model

6-8
Visualize the effects of multiplying a fixed positive number by positive numbers greater than 1 and less than 1.

### 6.2.1 Constant Cost Per Minute

6-8
Explore the total cost when the cost per minute for phone use remains constant over time.

### 6.2.2 Changing Cost per Minute

6-8
Explore the total cost when the cost per minute for phone use changes after the first sixty minutes of call.

### 6.3.1 Side Length and Area of Similar Figures

6-8
Learn about how the side lengths, perimeters, and areas of the two similar rectangles are related.