Video narration
Long multiplication for ×11 feels like more work than it should. I'm Mani, and your tens and ones digits show you a shortcut. Take 54 × 11. Keep the 5, the tens digit, and the 4, the ones digit, on the outside. Add them: 5 plus 4 equals 9. Put that sum between them: 5-9-4. So 54 × 11 equals 594. Now watch the carry. With 99 × 11, the outside digits are still 9 and 9, but 9 plus 9 equals 18. You can't place 18 in a middle spot. Put the 8 in the middle, and carry 1 into 9. That makes 1089. Now it's your turn: use the tens-and-ones pattern for 98 × 11. Add 9 and 8, carry when needed, and keep 8 on the right. What answer do you get? Comment it, and follow Mani for the method with numbers over 100 in the next video.