Learn powerful mental math techniques for quick addition and subtraction in this 31-minute video featuring "Mathemagician" Arthur Benjamin. Master strategies for effortlessly calculating one-, two-, and three-digit numbers in your head, including shortcuts using complement numbers. Discover practical applications for these skills, such as counting calories and making change. The video covers topics like adding and subtracting various digit numbers, using complement numbers, and applying these techniques to real-world scenarios. Perfect for math enthusiasts and anyone looking to enhance their mental calculation abilities.