Question

How is mental math to add with decimals different from adding whole numbers using mental math.

Answer 1

When using mental math to solve problems with decimals, it is harder to keep track of what number goes where and where the decimal spot goes as well. Although, with whole numbers in mental math, it is a lot easier to solve since there is no decimal and less numbers (unless you are doing whole number math with a large amount of numbers).

Answer 2

You have to add the decimal.