Question

How is adding decimals similar to adding whole numbers

Answer 1

If you know how to add and subtract whole numbers, then you can add and subtract decimals... to do this you put the numbers in a vertical column, aligning the decimal points. add each column of digits, starting on the right and working left. If the sum of a column is more than ten, "carry" digits to the next column on the left.

Answer 2

There both similar in a way seeing as you bring down the decimal and the answer an example would be

1
0.5
+ 0.8
---------
1.3