A. Let’s see how to multiply two-digit numbers by 11.

81 x 11 = ?

=8 (8+1) 1
=891

Step 1: First, add the two digits of the number (8 + 1 = 9).
Step 2: Write the value obtained in Step 1 between the two digits of the number.
So, 8 (9) 1 becomes 891.

53 x 11 = ?

=5 (5+3) 3
=583

Step 1: First, add the two digits of the number (5 + 3 = 8).
Step 2: Write the value obtained in Step 1 between the two digits of the number.
So, 5 (8) 3 becomes 583.

72 x 11 = ?

=7 (7+2) 2
=792
Method :
Step 1: First, add the two digits of the number (7 + 2 = 9).
Step 2: Write the value obtained in Step 1 between the two digits of the number.
So, 7 (9) 2 becomes 792.

95 x 11 = ?

=9 (9+5) 5
=9₁45  Carry forward the extra value: (The sum of 9 + 5 = 14, so keep the 4 and carry over 1 to the next place.)
= 1045

Step 1: First, add the two digits of the number (9 + 5 = 14).
Step 2: Write the result from Step 1 between the two digits of the number.
So, 9 (14) 5 becomes 9145.

65 x 11 = ?

=6 (6+5) 5
=6₁15   Carry forward the extra value: (The sum of 6 + 5 = 11, so keep the 1 and carry over 1 to the next place.)
= 715

Step 1: First, add the two digits of the number (6 + 5 = 11).
Step 2: Write the result from Step 1 between the two digits of the number.
So, 6 (11) 5 becomes 6115.

B. Multiplying any number by 11.

2123 x 11=?

Step 1: Start with the number 2123 and add zeros on both sides.
0 2123 0
Step 2: 0 2 1 2 3 0
Now, add the last digit (0) and the next digit (3) (0 + 3 = 3). Write the result below the line.
Step 3: 0 2 1 2 3 0
       3
Now, add the last digit (3) and the next digit (2) (3 + 2 = 5). Write the result below the line.
Step 4: 0 2 1 2 3 0
    3 5
Now, add the last digit (2) and the next digit (1) (2 + 1 = 3). Write the result below the line.
Step 5: 0 2 1 2 3 0
  3 3 5
Now, add the last digit (1) and the next digit (2) (1 + 2 = 3). Write the result below the line.
Step 6: 0 2 1 2 3 0
  2 3 3 5
Now, add the last digit (2) and the next digit (0) (2 + 0 = 2). Write the result below the line.
Final Result: 2123 × 11 = 23353