Shortcut to multiply any 2 digit number by 111

Shortcut to multiply 2 digit by 111 is one of those awesome tricks that you can use to quickly multiply any 2 digit number by 111. 

Let us now go through the steps

Step 1:Write down the unit place digit and the tenth place digit of the 2 digit number as follows

Step 2: Add the unit place digit and tenth place digit (2 + 1 = 3) and insert the sum as follows

Step 3:Repeat step 2 (2 + 1=3)and insert the sum as follows

Ans 12 x 111 = 1332

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Examples

Let us see few more examples to see how this works

Example 1: 13 x 111 = ?
Step 1:Writing down unit place digit and tenth place digit with 2 blanks in between them.We get 1_ _ 3

Step 2: Adding unit place digit and tenth place digit 
we get 1 + 3 = 4
Inserting the sum in between the unit place digit and tenth place digit

we get 1_ 4 3

Step 3: Again adding unit place digit and tenth place digit 
we get 1 + 3 = 4
Inserting the sum we get 1 4 4 3

Ans  13 x 111 = 1443

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Example 2:14 x 111 = ?
Step 1:Writing down unit place digit and tenth place digit with 2 blanks in between them.

We get 1_ _ 4

Step 2: Adding unit place digit and tenth place digit
we get 1 + 4 = 5
Inserting the sum in between the unit place digit and tenth place digit we get 1_ 5 4          

Step 3: Again adding unit place digit and tenth place digit 
we get 1 + 4 = 5

Inserting the sum we get 1 5 5 4

 Ans  14 x 111 = 1554

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Example 3:17 x 111 = ?
Step 1:Writing down unit place digit and tenth place digit with 2 blanks in between them.

We get 1_ _ 7

Step 2: Adding unit place digit and tenth place digit
we get 1 + 7 = 8
Inserting the sum in between the unit place digit and tenth place digit we get 1_ 8 7          

Step 3: Again adding unit place digit and tenth place digit 
we get 1 + 7 = 8

Inserting the sum we get 1 8 8 7

Ans 17 x 111 = 1887

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Example 4: 29 x 111 = ?
Step 1:Writing down unit place digit and tenth place digit with 2 blanks in between them.

We get 2_ _ 9

Step 2: Adding unit place digit and tenth place digit
we get 9 + 2 = 11
Inserting only the unit place digit of the sum in the blank between the unit place digit and tenth place digit . And carry forward ten’s place digit to step 3.

we get  2_ 1 9          

Step 3: Again adding unit place digit and tenth place digit 
 we get 9 + 2 = 11.

Now add carry forward from step 2(1).we get 11+1+12
Insert the one’s place digit(2) in the 3rd blank from right and carry forward ten’s place digit to step 4.

we get  2 2 1 9

Step 4: Add ten’s place digit(1) carry forwarded from step 3 to the original ten’s place digit. we get 1+2=3

Ans  29 x 111 = 3219

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Example 5: 23 x 111 = ?
Step 1:Writing down unit place digit and tenth place digit with 2 blanks in between them.We get 2_ _ 3

Step 2: Adding unit place digit and tenth place digit 
we get 3 + 2 = 5
Inserting the sum in between the unit place digit and tenth place digit

we get 2_ 5 3

Step 3: Again adding unit place digit and tenth place digit 
we get 3 + 2 = 5
Inserting the sum we get 2 5 5 3

Ans  23 x 111 = 2553

Now you try multiplying the following in 5 secs
(a)15 x 111 = ?
(b)16 x 111 = ?
(c)17 x 111 = ?
(d)18 x 111 = ?