In adding whole numbers with decimal points, here are the steps.
1. Arrange the numbers in such a way that the decimal points are aligned with each other.
2. Add the numbers normally like adding whole numbers. Do not mind the decimal point for now.
3. In the final answer, put a decimal point and align it with the others.
Hence, the sum of $5.89 and $1.15 is $7.04.
To summarize, the strategy is to align the decimal points of the two numbers and assume the numbers to be whole numbers and add them normally. In the final answer, put a decimal point and align it with the addends.