TheTimeCalculator.org - The time calculator helps you either add/subtract times in hours, minutes, and seconds to a given date.
MathCrunch - Learn math stress free
Calculator-online.net - The 100% free and reliable online calculators that help you to solve any calculation-related problems and provides you with the precise measurements.
Kalam Labs - Twitch for Science
SpeedCrunch - SpeedCrunch. SpeedCrunch is a high-precision scientific calculator featuring a fast, keyboard-driven user interface. It is free and open-source software, licensed under the GPL. Download Documentation Donate .
Fact Flow - Simple solution to help kids achieve math fluency