When multiplying decimals, the decimal point in the product is placed so that the number of decimal places in the product is equal to the __________ of the number of decimal places in the factors.

(a) product (b) sum (c) vertically (d) horizontally (e) and

sum

The answer is (b) sum.

When multiplying decimals, you count the number of decimal places in the factors. The decimal point in the product is then placed so that the number of decimal places in the product is equal to the sum of the number of decimal places in the factors.

To understand this concept better, let's look at an example:
Suppose we have two decimals, 2.5 and 3.75, and we want to multiply them.

Step 1: Count the number of decimal places in each factor.
- The first factor, 2.5, has one decimal place.
- The second factor, 3.75, has two decimal places.

Step 2: Find the sum of the number of decimal places in the factors.
- In this case, the sum is 1 + 2 = 3.

Step 3: Multiply the two decimals without placing the decimal point.
- 25 multiplied by 375 gives 9375.

Step 4: Place the decimal point in the product.
- Since the sum of the decimal places in the factors is 3, the decimal point is placed three places from the right in the product.
- The final product is 9.375.

So, the decimal point in the product is placed so that the number of decimal places in the product is equal to the sum of the number of decimal places in the factors.