Mental Math Tricks
Lesson 3 of 3 6 min +40 XP

Times 10 and Times 11

Spot the patterns that make big products easy.

What you'll learn

  • Understand times 10 and times 11
  • Apply it to real examples
  • Check yourself with a quiz
Adding a zero

Multiplying by 10 feels like magic: 34 × 10 is just 340 — slide a zero on the end. Once you see the pattern, whole rows of the times table become effortless.

Zero and mirror tricks

×10 appends a zero. ×11 for a single digit doubles the digit (3×11=33); for two digits, add the digits in the middle (23×11 = 2_(2+3)_3 = 253).

Knowledge Check

+10 XP / correct

1. 45 × 10 = ?

2. 7 × 11 = ?