Multiply any number by 11 in your head
किसी भी संख्या को 11 से मन में गुणा करें
Add neighbouring digits and place the sums between the first and last digit. Works for two-digit and longer numbers, with a simple carry rule.
पहले और आखिरी अंक के बीच पड़ोसी अंकों का योग लिखें; 9 से बड़ा हो तो हासिल आगे जोड़ें।
Two-digit numbers
- Keep the first and last digit.
- Put their sum in the middle.
- If the sum is 10 or more, write its last digit and add 1 to the first digit.
Example 52 × 11
5 | 5+2 | 2 → 572
Example 87 × 11
8 | 15 | 7 → carry 1 → 957
Example 63 × 11
6 | 9 | 3 → 693
Three digits or more
Write the last digit, then the sum of each neighbouring pair moving left, then the first digit. Carry as usual.
Example 234 × 11
2 | 2+3 | 3+4 | 4 → 2574
Example 456 × 11
4 | 9 | 11 | 6 → from the right: 6, 11 → 1 carry 1, 9 + 1 = 10 → 0 carry 1, 4 + 1 = 5 → 5016
Try it yourself · अभ्यास
- 78 × 11 = ?
Show answer
7 | 15 | 8 → 858
- 99 × 11 = ?
Show answer
9 | 18 | 9 → 1089