If the number is multiplied by 12 to 19 then following method is to be followed.
Let’s understand this method by taking an example.
345 × 12
Step 1:
Write 345 as 0345.
Step 2:
Multiply each and every digit with 2 and add it to its right neighbor. This process is started from right. Multiply 5 with 2 and add it to its right neighbor. 5 has no right neighbor so add the multiplication to 0. This gives 10 as a result. So 0 is written down and 1 is carried forward.
Step 3:
Multiply 4 with 2 and add it to 5. Carry 1 is added to the result. This gives 14 as a result.
4 is written down and 1 is carry forwarded.
Step 4:
Multiply 3 with 2 and add it to 4. Carry 1 is added to the result. This gives 11 as a result.
1 is written down and 1 is carry forwarded.
Step 5:
Multiply 0 with 2 and add it to 3. Carry 1 is added to the result. This gives 4 as a result.
You can take this procedure as standard procedure.
Now, if the number is multiplied by 13 then multiply each and every digit with 3 instead of 2. And rest of the procedure is same.
If the number is multiplied by 14 then multiply each and every digit with 4 instead of 2. And rest of the procedure is same.
If the number is multiplied by 15 then multiply each and every digit with 5 instead of 2. And rest of the procedure is same.
If the number is multiplied by 16 then multiply each and every digit with 6 instead of 2. And rest of the procedure is same.
If the number is multiplied by 17 then multiply each and every digit with 7 instead of 2. And rest of the procedure is same.
If the number is multiplied by 18 then multiply each and every digit with 8 instead of 2. And rest of the procedure is same.
If the number is multiplied by 19 then multiply each and every digit with 9 instead of 2. And rest of the procedure is same.
