Which statement correctly describes the placement of the decimal in the product when multiplying decimals?

• A. Place the decimal so the product has a number of decimal places equal to the sum of the decimal places in the factors.
• B. Place the decimal so the product has more decimals than either factor.
• C. Place the decimal in the product only if both factors are integers.
• D. Place the decimal in the product equal to the larger number of decimals in a factor.

Answer: (A)

When you multiply decimals, the decimal in the product is determined by the sum of the decimal places in the factors. Each decimal place represents a fractional power of ten (tenths, hundredths, thousandths, etc.), and multiplying decimals effectively combines those fractional parts, so you shift the decimal point to reflect all the decimal places involved.

For example, 0.12 has two decimal places and 3.4 has one; their product is 0.408, which has three decimal places—the sum of 2 and 1.

So the statement that the product’s decimal places equal the sum of the decimal places in the factors is the best description. The other ideas fail because the product does not necessarily have more decimals than both factors, decimals aren’t conditional on both factors being non-integers, and the number of decimals isn’t always just the larger of the two counts.