Multiply 0.6 × 0.25.

• A. 0.375
• B. 0.15
• C. 0.25
• D. 0.6

Answer: (B)

When you multiply decimals, first ignore the decimal points and multiply the numbers as if they were whole numbers. Then count how many digits are to the right of the decimal in the factors and place the decimal point in the product so there are that many digits after the decimal.

In 0.6 there is 1 digit after the decimal, and in 0.25 there are 2 digits after the decimal, so the product should have 3 digits after the decimal. Multiply 6 by 25 to get 150. Put the decimal point three places from the right to get 0.150, which is the same as 0.15.

Placing the decimal differently would change the value, so 0.15 is the correct result.