Speed Math EP21 - Marathon Edition | Three Chains. That's the Whole Video.

Follow the chain from start to finish without losing your place. Marathon: three enormous twenty-element chains with a 20-second clock. HOW IT'S SCORED: everything is calculated strictly left to right, like a calculator — NOT using BODMAS/PEMDAS order. 12 + 8 × 2 here is (12+8)×2 = 40. Drop your score in the comments — and if a specific question got you, quote it by its tag (EP21 Q7) so others can compare. A new challenge every day. Subscribe so tomorrow's set finds you. #SpeedMath #MentalMath #MathChallenge #MindMathAndYou #BrainTraining #MentalWorkout #NoCalculator #WorkingMemory #MarathonEdition