Question

When adding decimals by hand, you must:

A) Line up the numbers to the left, then add from left-to-right.

B) Line up the decimals of the numbers, then add from left-to-right.

C) Line up the decimals of the numbers, then add from right-to-left.

D) Line up the numbers to the left, then add from right-to-left.

Answer 1

To add decimals by hand, you must line up the decimals of the numbers and add from right-to-left, ensuring that place values are matched correctly; then, if necessary, round off the result to the precision of the least precise decimal.

Step-by-step explanation:

When adding decimals by hand, the correct procedure is: C) Line up the decimals of the numbers, then add from right-to-left. This ensures that you are adding digits with the same place value correctly. To provide additional clarity, here is the step-by-step method for adding decimals:

1. Align the decimal points of the numbers vertically so that the tens, ones, tenths, hundredths, etc., are in the same columns.
2. Insert zeros as place holders if one number has fewer digits than the other.
3. Add from right-to-left, starting with the smallest place value (decimal places), and move towards the largest place value, carrying over when needed.
4. If necessary, round the result to the same number of decimal places as the number with the least number of decimal places (the least certain value).