You could see demails in numbers,math,or money.
Not in the way we that would use a decimal point today. But they did use points to signify fractions of 12.
Forty cent as decimal
1.786 rounded to two decimal points would be 1.79
There should be no points after the decimal point.
7.00
87.656 87.66
You would round it DOWN - to 25.30
If there are any numbers which are integers and so do not have a decimal point, then append one at the extreme right. Then arrange all the numbers in a column, with their decimal points aligned. Ad up the numbers ignoring the decimal points entirely. In the answer insert a decimal point under the column of decimal points.
It is 562.68
The main difference is that with whole numbers the decimal point is "hiding" (after the last digit of each whole number) whereas with decimal numbers it is clearly visible. In both cases the numbers are added with the decimal points aligned - with whole numbers there are no digits after the decimal points so the decimal points are not written, but if they were they would be visible after the last digit of the whole numbers and they would be automatically aligned; with decimal numbers there may be a different number of digits after each decimal point so it is up to the person doing the arithmetic to ensure the decimal points are aligned.
Decimal points aren't positive or negative. Decimals can be either.
Put the numbers in a column with the decimal points aligned. Add the numbers ignoring the decimal points. Insert the decimal point in the answer exactly below the column of decimal points in the numbers being added (summands).