Virtual Manipulative Demonstration Virtual Geoboard By Emily Ibanez

History • Geoboards are grids of pegs that can hold rubber bands in position. • Invented by the English mathematician Caleb Gattegno (1911 -1988).

The National Library of Virtual Manipulatives http: //nlvm. usu. edu/en/nav/vlibrary. html

Virtual Geoboard Demonstration Geometry 1. Show a triangle. 2. Show a square. 3. Show a polygon. Measurement 1. Show a triangle that has an area of one square unit. 2. Show a shape with an area of 2 square units. What shape is it? Fractions 1. Determine different ways to divide the geoboard into 4 equal areas. 2. Show me two halves.

Virtual Geoboard Demonstration Virtual Geoboards available for Geometry and Measurement all grade levels.

Virtual Geoboard Components

First Geometric Demonstration Geometry Grades Pre-K-2 Color the inside of each triangle green. Color the squares yellow.

Demonstration Continued… Geometry Grades Pre-K-2 1. How many gray squares will fit in the yellow rectangle? 2. How many will fit in the green rectangle? 3. How many will fit in the blue rectangle? 4. Which rectangle has the largest area?

Demonstration Continued… Measurement Grades Pre-K-2 Touch Six Pegs Here is a geoboard shape that touches exactly three pegs: Build a shape that touches exactly six pegs.

Demonstration Continued… Geometry Grades 6 -8 Creating Shapes with Perimeter 16 Draw three different shapes that have a perimeter of 16.

Demonstration Continued… Geometry Grades 3 -5 Open and Closed To complete this activity: Use one or more geobands to make a shape where the ends do not meet. An open figure is one where the ends do not meet. Use one geoband to make a shape where the ends meet. How are the shapes alike and different? Make two open and two closed figures that have three sides. Look around you and identify where you see open and closed shapes.

Demonstration Continued… Fractions Grades Pre. K-2 Exploring Patterns Created by Dividing Shapes To complete this activity: Make the largest square possible. Use a geoband to divide the square into two equal regions. Divide one of the regions again. What shapes are formed? Is there a pattern?

Virtual Geoboard The National Library of Virtual Manipulatives http: //nlvm. usu. edu/en/nav/vlibrary. html