Unit 1 Number Systems CFA Review

What are additive inverses? (hint: p. 21)

• Numbers that are multiplied to get one

• Numbers that add up to zero

• Numbers that are divided to get one

• Numbers that subtract to get zero

Give an example of a number and its additive inverses.

• 5 and -5

• 3 and 3

• 7 and 1

• 2 and 4

Which scenario below represents opposites that combine to make zero?

• Jamal ran up 3 flights of stairs and then down 4 flights of stairs.

• Harmony climbed 5 feet up into a tree and then climbed another 5 feet up in the tree.

• Sophia borrowed $10 from her friend on Monday and then paid back her friend $10 on Tuesday.

• The temperature is 12° during the day but drops 2° at night. The temperature is now 10°.

Write a scenario or word problem that uses additive inverses.

• A person climbs 10 steps up and then 10 steps down.

• A person buys 5 apples and then buys 3 more apples.

• A person walks 2 miles north and then 1 mile south.

• A person saves $20 and then spends $10.

Brian borrows $2.75 from his older sister to buy some Hot Fries. Then he borrows $4.50 from his friend to pay a movie fine. Using negative numbers, write an equation to express Brian’s total debt that day.

• -2.75 - 4.50 = 7.25

• • 2.75 - 4.50 = -7.25

• -2.75 - 4.50 = -7.25

• • -2.75 -4.50 = -1.75

The temperature in the morning was 7°C. The temperature drops 19°C by midnight. What is the temperature at midnight?

• 26°C

• -12°C

• -19°C

• 12°C

Rudy is hiking up a mountain and stops at 105 3/4 feet above sea level when he kicks a ball. The ball falls down the mountain and stops at 10.5 feet below sea level. What is the vertical distance the ball fell? Use the image below to help you.

• 116.25 feet

• 95.25 feet

• 115.75 feet

• 105.75 feet

Which expression is represented by the number line below?

• 2 + -3

• 2 + 3

• 2 + -5

• -3 + 2

• 2 + 5

The number line represents Mike’s score scores in the first two rounds of a game. Mike started the game with 0 points. What was Mike’s score after the first round?

• -8

• 0

• 8

• -10

How many points did Mike have after the first two rounds?

• 0

• -8

• 8

• -16