Which sustainability innovation has had the greatest impact on reducing the environmental footprint of calculators in the past decade?

Modern mathematics education is increasingly embracing sustainability. From eco-friendly classroom materials to energy-efficient calculation tools, the math education industry is finding innovative ways to reduce its environmental footprint. This poll tests your knowledge about one significant sustainability initiative that transformed a ubiquitous mathematical tool. How much do you know about the evolution of calculators and their environmental impact?

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

Solar-powered calculators that eliminate the need for disposable batteries
Calculators made from biodegradable corn-based plastics
Calculator trade-in programs that recycle 90% of components
Digital calculator apps that have completely replaced physical devices