How to add natural numbers: calculate the sum and learn to add multiple digit numbers, column addition method, from right to left

Let's learn with an example.
The natural numbers to add:
399 + 675 + 412

Method used below: column adding, from right to left (traditional).

Stack the numbers on top of each other.

The ones digits line up in the first column from the right.

The tens digits line up in the next column to the left.

And so on...


  399
  675
+  412

?

Add column by column; start from the column on the right.

Add the digits in the ones column:

9 + 5 + 2 = 16

How did we add the digits? Explanation below.

Group the ones together in order to make tens:


9 + 5 + 2 =


9 + 5 + 2 =


9 + 7 =


9 + 7 =


9 + 1 + 6 =


9 + 1 + 6 =


10 + 6 =


16


Change the order in which the numbers are added, the sum stays the same.
Break some number(s) into component parts, the sum stays the same.


The sum is a two-digit number: 16.


6 is the ones digit.
Write it down at the base of the ones column.


1 is the tens digit.
Carry it over to the tens column.
Write the digit above that column.
Add it with the rest of the digits in that column.

   1
  399
  675
+  412

    6

Add the digits in the tens column:

9 + 7 + 1 + 1 = 18

How did we add the digits? Explanation below.

Group the ones together in order to make tens:


9 + 7 + 1 + 1 =


9 + 7 + 1 + 1 =


(9 + 1) + 7 + 1 =


10 + 7 + 1 =


10 + 7 + 1 =


10 + 8 =


18



The sum is a two-digit number: 18.


8 is the tens digit.
Write it down at the base of the tens column.


1 is the hundreds digit.
Carry it over to the hundreds column.
Write the digit above that column.
Add it with the rest of the digits in that column.

  11
  399
  675
+  412

   86

Add the digits in the hundreds column:

3 + 6 + 4 + 1 = 14

How did we add the digits? Explanation below.

Group the ones together in order to make tens:


3 + 6 + 4 + 1 =


3 + 6 + 4 + 1 =


3 + 10 + 1 =


3 + 10 + 1 =


10 + (3 + 1) =


10 + 4 =


14



The sum is a two-digit number: 14.


4 is the hundreds digit.
Write it down at the base of the hundreds column.


1 is the thousands digit.
Write it down at the base, next to the hundreds digit.

  11
  399
  675
+  412

 1486

Answer:

399 + 675 + 412 = 1.486


>> Adding natural numbers calculator: calculate the sum and learn how to add multiple digit numbers