Prism Lab vs Geoboard, by MLC

Prism Lab is an optics bench in your pocket. Put a piece of glass on the graph paper, aim the laser at it, and watch the light bend, bounce and split, with every angle measured for you. It follows the experiments from a school ray box kit, so it works as a companion to the lab or on its own. THE BENCH • Nine pieces: a simple surface, 45-90-45 and 60-60-60 prisms, rectangle, square, semicircle, convex and concave lenses, and an optical fibre. • Drag the laser and where it aims. The angles of incidence, refraction and reflection update as you move. • Tap any angle and type the value you want. The laser swings there so you can see how it gets to it. • One, three or five parallel beams, to find the focus of a lens. MATERIALS • 119 materials for the piece and for what surrounds it: glasses, liquids, gems and gases, each with its refractive index. • The critical angle is worked out for every pair, and you can see total internal reflection happen. COLOUR • White light opens into a spectrum, because each colour bends by its own amount. • 77 materials use published dispersion data. For the rest the app tells you the spread is an estimate. • Red, yellow, green, blue and violet lasers, in the width you choose. LIGHTS OFF • Turn the lights off and the beams glow, as in a dark classroom. NO STRINGS • No account, no ads, and no data collected. • Everything is free. If you find it useful you can buy the developers a coffee. In English, Spanish and French, for iPhone and iPad.

Geoboard is a tool for exploring a variety of mathematical topics introduced in the elementary and middle grades. Learners stretch bands around the pegs to form line segments and polygons and make discoveries about perimeter, area, angles, congruence, fractions, and more. This virtual version of the manipulative is an open-ended educational tool, ideal for elementary classrooms and other learning environments. FEATURES • Create line segments and polygons by stretching bands around the Geoboard’s pegs. • Choose from 8 different band colors. • Fill individual shapes with a transparent color, or use the Fill All button to toggle all the bands between filled and unfilled. • Switch between the standard 25-peg square board, a rectangular board with 150 pegs, or a circular board with 13 pegs. The circular board enables explorations with angles, fractions, and time measurement. • Duplicate shapes then move, rotate, or flip them to explore symmetry and congruency. • Change the color of selected bands. • Display grid lines with or without numbering to more easily calculate area and identify shape locations. •Hide and reveal work with resizable covers to create your own problems and model strategies. • Use the drawing tools to annotate work and show understanding. • Add equations, expressions, and descriptions with the math text and writing tools. • Share your work by saving an image or providing a share code to others. MORE APPS For more Geoboard resources and other apps, visit:www.mathlearningcenter.org/apps LEARN MORE To learn about Bridges in Mathematics, an elementary curriculum that employs visual models such as the geoboard, please visit: www.mathlearningcenter.org/bridges/overview ABOUT US This app is brought to you by The Math Learning Center, a nonprofit organization dedicated to K-12 math education since 1976. ACKNOWLEDGEMENTS The Geoboard app was made possible by a generous donation from Dr. David Moursund. This app was crafted by Clarity Innovations. We help improve teaching and learning by creating solutions that match promising technologies with the needs of education.  Visit us at: www.clarity-innovations.com