Sample Decimal Problems and Answers

What Are Some Tips for Solving Decimal Problems?

When your child adds or subtracts decimals, make sure he or she lines up the decimal points in the problem and answer. For instance, 4.72 + 5.941 can be set up vertically as follows:

4.72

5.941

After your child has added these numbers, make sure that the decimal point in his or her answer corresponds correctly. For instance, the answer for this problem is 10.661. Note that the decimal point in the answer is in the same position as it was in the question - in the hundredths place. In some cases, your child will have to fill in places with zeros in order to add. Consider the following problem: 5.1 - 3.45. In this instance, the hundredths place in the first number has to be filled in with a zero, like this:

5.10

3.45

Unlike addition, when multiplying decimals, your child should not line up the decimal points. Instead, remind your child to count the digits after the decimal point. For example, 4.72 has two digits after the decimal point and 5.9 has one. Now ask your child to add those amounts. In this case, we are dealing with a total of three digits. Your child's answer should reflect a decimal point position that has exactly three numbers after the decimal point, like this: 4.72 x 5.9 = 27.848.

Remind your child that because he or she is multiplying multiple digits, each top number has to be multiplied by each bottom number. Then instruct your child to add the products. When you give these problems to your child, format them so the equations are vertical.

Sample Decimal Problems and Answers

Addition and Subtraction

1. 8 - 3.41

The answer for this problem is 4.59. Remind your child to fill in the tens and hundredths places for the first number, so it should look like this: 8.00 - 3.41.

2. 13.12 + 1.45

Both of the numbers in this problem have places in the tens and hundredths place; so the answer should also have two digits after the decimal place. The answer is 14.57.

3. 20.77 - 15.6601

The answer to this problem is 5.1099.

Multiplication

1. 5.888 x 1.2

The answer is 7.0656. Notice how it has four numbers after the decimal point, because the first number has three digits after the decimal point and the second number has one digit in the tens column, resulting in four numbers total.

2. 12.01 x 3.3

The solution is 39.633.