Math 8 Lesson 0 Quiz

Normally, the freezing point for water is 32°F. A city treats its streets before a snowstorm. On the treated streets, the freezing point for water changes by -38°F. What is the new freezing point for water on the treated streets?

• -6°F

• 6°F

• -70°F

• -38°F

Normally, the freezing point for water is 32°F. A city treats its streets before a snowstorm. On the treated streets, the freezing point for water changes by −38°F. What is the new freezing point for water on the treated streets?

• -6°F

• 6°F

• -38°F

• -70°F

The new freezing point is shown on the number line. What is the new freezing point?

• The new freezing point is the point marked on the number line below zero.

• The new freezing point is always at zero on the number line.

• The new freezing point is above zero on the number line.

• The new freezing point cannot be shown on a number line.

Both Model Its use zero pairs in which of the following ways?

• To represent adding and removing values

• To multiply numbers

• To divide numbers

• To compare fractions

Explain how you can find 38 + (−32).

• By adding 38 and -32 to get 6.

• By subtracting 32 from 38 to get 70.

• By multiplying 38 and -32 to get -1216.

• By adding 38 and 32 to get 70.

Without finding the sum, how do you know −32 + (−38) is negative?

• Both numbers are negative, so their sum is negative.

• One number is positive and one is negative, so the sum is negative.

• Both numbers are positive, so their sum is negative.

• The numbers cancel each other out, so the sum is zero.

The sum of two integers can be positive, negative, or zero because:

• integers can be both positive and negative, so their sum varies accordingly.

• the sum of two integers is always positive.

• the sum of two integers is always negative.

• integers cannot be added together.

Reflect: One of the models or strategies discussed today helped you better understand adding negative integers. Which of the following is an example of such a strategy?

• Using a number line to visualize adding negative numbers

• Memorizing multiplication tables

• Practicing only with positive numbers

• Ignoring negative signs when adding

A dragonfish is swimming at −900 m relative to sea level. It rises 250 m. What is the dragonfish’s new depth relative to sea level?

• -650 m

• -1150 m

• -900 m

• -250 m

What is 79 + (−26)?

• −105

• −53

• 53

• 105