Integers and their opposites

Samuel has $20 in his savings account before he makes a deposit of $160. After 2 weeks, he withdraws $160. How did Samuel’s savings account balance change?

• Increased by $160
• Decreased by $160
• No change
• Increased by $20

When preparing for a rocket launch, the mission control center uses the phrase “T minus” before liftoff.

…T minus 3, T minus 2, T minus 1, …

After the rocket has launched, “T plus” is used while the rocket is in flight.

…T plus 1, T plus 2, T plus 3, …

When does the rocket launch? What could “T” represent?

• T represents the time of launch
• T represents the temperature of the rocket
• T represents the trajectory of the rocket
• T represents the thrust of the rocket

The temperature was 75^º. At noon, the temperature increased 7^º. By evening, the temperature decreased by 7^º. How did the temperature change?

• The temperature increased by 7º
• The temperature decreased by 7º
• The temperature remained the same
• The temperature increased by 14º

Samuel has $80 in his savings account before he makes a deposit of $100. After 2 weeks, he withdraws $100. How did Samuel’s savings account balance change?

• Increased by $80
• Decreased by $100
• Increased by $100
• No change

Samuel has $60 in his savings account before he makes a deposit of $120. After 2 weeks, he withdraws $120. How did Samuel’s savings account balance change?

• Increased by $60
• Decreased by $60
• No change
• Increased by $120

Lucy has $100 in her savings account. She deposits $200. After a month, she withdraws $200. How did Lucy’s savings account balance change?

• Increased by $100

• Decreased by $100

• No change

• Increased by $200

During a space mission, the control center uses the phrase 'L minus' before the lunar landing.

...L minus 3, L minus 2, L minus 1, ...

After the lunar landing, 'L plus' is used while the astronauts are on the moon.

...L plus 1, L plus 2, L plus 3, ...

When does the lunar landing occur? What could 'L' represent?

• L represents the lunar landing time

• L represents the lunar module

• L represents the lunar surface temperature

• L represents the lunar orbit

John has $120 in his savings account before he makes a deposit of $150. After 3 weeks, he withdraws $150. How did John’s savings account balance change?

• Increased by $120

• Decreased by $150

• Increased by $150

• No change