To add numbers with decimals, line up all the numbers vertically so that the decimal places are in a vertical line. Add each column of digits, starting on the far right and carrying over digits to the next column if any column adds up to more than 10.
Adding numbers with decimals is similar to adding whole numbers. In both cases, line the numbers up vertically so that each place value matches vertically to the places values in other numbers. When adding, simply drag the decimal straight down where it exists in the column. If one number has more place values to the right or to the left of the decimal point than other numbers have, simply add the existing numbers as though the digit zero exists in those columns.