Jeff Bezos teaches his kids math with a strategy that's made Singaporean students the best in the world — here's how it works

• Jeff and MacKenzie Bezos use an approach called Singapore math to teach their kids mathematics.• It's used predominantly in South Asia.• Singaporean students outperformed those from all other countries on a math exam in 2015. Jeff Bezos, the Amazon CEO and richest person in the world, has amassed his …