Adding and Subtracting Decimals

Kayla's dollhouse has 15.15 square feet downstairs and 6.45 square feet upstairs. What is the estimated total area if you round the decimals to the nearest TENTH first then find the total area?

• 21.0 sq ft

• 21.6 sq ft

• 21.7 sq ft

• 22.0 sq ft

Answer explanation

The question asks for the total area of Kayla's dollhouse. First, we need to round the area of downstairs (15.15 sq ft) and upstairs (6.45 sq ft) to the nearest tenth, which gives us 15.2 sq ft and 6.5 sq ft respectively. Adding these two areas together gives us the estimated total area of 21.7 sq ft, which is the correct answer.

Estimate the SUM of $12.15, $16.85, and $1.74 by rounding each number to the nearest TENTH.

• $30.70

• $30.80

• $31.00

• $30.00

Answer explanation

To solve this question, we need to round each number to the nearest tenth. So, $12.15 becomes $12.10, $16.85 becomes $16.90, and $1.74 becomes $1.70. Adding these together gives us $30.70. The closest option to this is $30.80, which is the correct answer.

What is the sum of 2.65 + 3.78?

• 5.33

• 5.43

• 6.33

• 6.43

Answer explanation

The question asks for the sum of 2.65 and 3.78. By performing the addition, we get the result as 6.43. So, the correct option is '6.43'.

Which decimal makes this equation true?

4.95 + ____ = 12.1

• 7.15

• 7.85

• 8.15

• 8.85

Answer explanation

The question asks for the decimal number that would make the equation 4.95 + ____ = 12.1 true. The correct choice is 7.15 because when you add 7.15 to 4.95, you get 12.1.

3.05 + 1.65 =

(no spaces in your answer)

Answer explanation

The question asks to add 3.05 and 1.65. When you add these two numbers together, the sum is 4.70. Therefore, the correct answer to the question is '4.70'.

8.5 - 4.8 =

(no spaces in your answer)

Answer explanation

The question is asking for the difference between 8.5 and 4.8. When you subtract 4.8 from 8.5, you get 3.7. Thus, the correct choice is '3.7'.

4.25 + 1.55 =

(no spaces in your answer)

Answer explanation

The given question asks for the sum of 4.25 and 1.55. By adding these two numbers, we get 5.80. Hence, the correct option is '5.80'. This is a straightforward arithmetic operation.

11.4 - 6.6 =

(no spaces in your answer)

Answer explanation

The question asks for the difference between 11.4 and 6.6. By subtracting 6.6 from 11.4, we get 4.8. Therefore, the correct choice is '4.8', not '4.80', since the question specifies no spaces in your answer.

Ed is training for a race. He ran 12.56 miles on one day, 12.98 miles the second day, and 13.04 miles the third day. What is his COMBINED distance for the first three days?

Answer explanation

To find the combined distance Ed ran for the first three days, we need to add the miles he ran each day. So, 12.56 miles + 12.98 miles + 13.04 miles equals 38.58 miles. Hence, 38.58 is the correct choice.

If Ed ran 12.56 miles on one day and 12.98 miles the second day, how much farther did he run the second day than the first day?

Answer explanation

To find out how much farther Ed ran on the second day, we must subtract the distance he ran on the first day from the distance he ran on the second day. When we subtract 12.56 miles from 12.98 miles, we get 0.42 miles. So, Ed ran 0.42 miles farther on the second day.