Thank you for your interest in NCTM’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

### Three Sides

Pre-K-2
In this lesson, students compare and contrast shapes using attribute blocks. Because the equilateral triangle (a triangle with congruent sides and congruent angles) is the most common example used in textbooks and other reference materials, this is an important opportunity for you to help students realize that other triangles exist and that triangles can have angles of different measures. The lesson is designed to accommodate multiple learning styles and intelligences.

### Tracing and Drawing

Pre-K-2
In this lesson, students continue to discuss attributes of triangles. They  trace and draw triangles individually. Students recognize objects in their environment that are shaped like triangles and explain to the class how they recognized the shape.

### Geoboards

Pre-K-2
Students use appropriate vocabulary to describe shapes to their classmates. Students focus on the properties of shapes to develop mental images of objects from descriptors. They create multiple representations of triangles using geoboards, string, and crayons and paper.

### Focus on Two

Pre-K-2
A nursery rhyme provides a context for using the number 2. Students make groups of two, write the numeral 2, and record a group of two on a personal recording chart.

### Three in a Set

Pre-K-2
In this lesson, students construct sets of three, compare them with sets of two, and write the numeral 3. They also show a set of three on their recording chart.

### One, Two, Three--Go

Pre-K-2
After reviewing the numbers 2 and 3, students construct and identify sets of one. They compare sets of one, two, and three objects and record a set of three in chart form.

### Finding Four

Pre-K-2
Students explore the number 4. They make sets of four, write the numeral 4, and compare sets of four to sets of one, two, and three.

### Here's a Handful

Pre-K-2
Students construct sets of up to five items, write the numeral 5, identify sets of five, and record "5" on a chart. They also play a game that requires recognizing the numerals to 5. This lesson provides opportunities for connecting mathematics with music.

### Zero Our Hero

Pre-K-2
Students explore sets of zero items and practice writing the numbers 0 through 5. Students count back from five, identify sets of up to five items, and record "0" on a chart. They also construct sets of up to five items.