Adding and Subtracting Decimals

What is the result of 80.93 - 68?

• $10.93

• $12.93

• $14.93

• $16.93

What is a common mistake when adding or subtracting decimals?

• Misaligning the decimal points, which can lead to incorrect results.

• Using the wrong operation (addition instead of subtraction).

• Forgetting to carry over numbers when necessary.

• Rounding the numbers before performing the operation.

How do you determine how much more one amount is than another?

• Add the two amounts together.

• Multiply the larger amount by the smaller amount.

• Subtract the smaller amount from the larger amount.

• Divide the larger amount by the smaller amount.

How do you find the total weight of fruits picked if 12.34 pounds of apples and 9.56 pounds of raspberries are picked?

• 20.5 pounds

• 21.9 pounds

• 22.3 pounds

• 19.8 pounds

How do you align decimals when performing addition or subtraction?

• You align the decimal points of the numbers vertically to ensure that each digit is in the correct column.

• You add a zero to the end of the longer number before aligning.

• You align the numbers based on their largest digit.

• You ignore the decimal points and align the numbers as whole numbers.

How can you check your work after adding or subtracting decimals?

• By reversing the operation: for addition, subtract the sum from one of the addends; for subtraction, add the result to the subtracted number.

• By rounding the numbers to the nearest whole number and checking if the result is reasonable.

• By using a calculator to verify the final answer only.

• By writing the problem in a different format and solving it again.

What tools can help with adding and subtracting decimals?

• Calculators, number lines, and decimal grids

• Only calculators

• Only number lines

• Only decimal grids

What is the value of 100.65 - 65.84?

• $30.75

• $34.81

• $36.12

• $32.50

If a family drives for 10.9 hours, 8.6 hours, and 12.4 hours, how do you find the total driving time?

• Multiply the three time durations together: 10.9 * 8.6 * 12.4 = 1,000.4 hours.

• Add the three time durations together: 10.9 + 8.6 + 12.4 = 31.9 hours.

• Subtract the shortest duration from the longest: 12.4 - 8.6 = 3.8 hours.

• Divide the total time by the number of trips: (10.9 + 8.6 + 12.4) / 3 = 10.3 hours.

What is the process of subtracting decimals?

• Align the numbers by the decimal point and subtract each column starting from the right, borrowing if necessary.

• Add the numbers together starting from the left.

• Multiply the numbers and then subtract the product from the larger number.

• Convert the decimals to fractions and then subtract.