4.1 Multiplication (2018)

Advanced multiplication tricks added in the 2018 revision.

Lessons

• 4.1.1 Multiplying Three-Digit Number by Two-Digit Number
• 4.1.2 Multiplying Three-Digit Number by Three-Digit Number
• 4.1.3 Multiplying Two Numbers Whose Units Add to 10
• 4.1.4 Binomial Approximation
• 4.1.5 Multiplying by Fraction Close to 1
• 4.1.6 n² + n = (n + 1)² - (n + 1)