Sometimes adding longhand can get complicated when you are not certain of how to add longhand to begin with. Take a deep breath before you begin in order to clear your head and allow for simpler thinking.
Using a piece of paper and a pencil or pen, write the numbers one above the other aligned to the right. Add one column at a time beginning from the right and working toward the left, making sure to write the sums of the columns directly below the column that is being added. Use normal addition tactics to acquire the sum -- e.g., 7 + 2 = 9.
Example:
37
+ 22
----------
59
Using a piece of paper and a pencil or pen, write the numbers one above the other aligned to the right. Add one column at a time beginning from the right and working toward the left, placing the right number of a two-digit sum beneath each column and carrying the left number to the top of the next column.
Example:
199
+ 72
-----------
271
While having a decimal point appear within a set of numbers that need to be added may seem to be confusing or overwhelming, adding decimals is as simple as adding regular whole integers. When lining up the numbers to be added, make sure that the decimal points line up one above the other.
Example:
89.2
+ 100.3
Once the numbers are lined up, add the columns exactly as if they were whole integers, working with one column at a time starting from the right and moving left.
Example:
89.2
+ 100.3
-----------
189.5
When adding a number that contains a decimal to a whole number that does not have a decimal point, you can write in ".0" after the whole number to make addition simpler. Then you can follow the same addition rules that apply to all addition sequences, adding the columns exactly like whole integers, working with one column at a time starting from the right and moving left.
Example:
37.7
+ 27.0
---------
64.7
If there is more than one number following a decimal point, an equal number of zeros can be added to the whole integer.
Example:
42.35
+ 23.00
------------
65.35