Desmos Graphing Calculator - Graph functions, plot data, evaluate equations, explore transformations, and much more – for free! Also available as an app on Google Play and Apple App Store
Calculate84 - a graphing calculators for iPhones
CALC 84 - a graphing calculator 83/84
Wabbitemu - creates a Texas Instruments graphing calculator right on your Windows, Mac, or Android device.
The Inside Mathematics Problem Solving problems are non-routine math problems designed to promote problem-solving in your classroom. Each problem is divided into five levels of difficulty to allow access and scaffolding for students into different aspects of the problem and to stretch students to go deeper into mathematics complexity.
Desmos Classroom Activities
Access digital math activities that engage students into problem solving, thinking and reasoning. Premade Desmos activities are available but teachers can create their own.
Real World Tasks: Have you used Robert Kaplinsky's Open Middle Tasks and Real-World Problems? Great resources of math tasks that promote problem solving and reasoning.
Geogebra + Illustrative Mathematics
Do you use Illustrative Mathematics to supplement lessons ad GeoGebra as a tool? Access free Illustrative Math in GeoGebra now!