Adding Rational Numbers in the Real World: Decimals

The video tutorial explains how to calculate temperature changes over time by adding rational numbers. It covers the addition of negative numbers and the process of determining the total temperature change from 5:00 PM to midnight. The tutorial also demonstrates how to find the final temperature at midnight by adding numbers with different signs, emphasizing the importance of absolute values and sign determination. The lesson concludes with a real-world application of these mathematical concepts.

What is the total temperature change from 5:00 PM to midnight if the temperature dropped by 5.5 degrees and then by 3.9 degrees?

• -9.4 degrees

• -7.4 degrees

• -8.4 degrees

• -10.4 degrees

When adding two negative numbers, what is the first step?

• Multiply their absolute values

• Add their absolute values

• Subtract their absolute values

• Divide their absolute values

If the temperature at 5:00 PM was 85.2 degrees and it changed by -9.4 degrees, what is the temperature at midnight?

• 77.8 degrees

• 75.8 degrees

• 74.8 degrees

• 76.8 degrees

How do you determine the sign of the result when adding numbers with different signs?

• Always use a negative sign

• Always use a positive sign

• Use the sign of the larger number

• Use the sign of the smaller number

What is the result of 85.2 minus 9.4?

• 77.8

• 75.8

• 74.8

• 76.8