Using Negative Numbers in Real Life

Steve has overdrawn his checking account by $27. His bank charged him $15 for an overdraft fee. Then he quickly deposited $100. What is his current balance?

Steps to Solve

• Overdrawn $27 = -27
• Bank fee $15 = -27-15
• Now Steve owes -42
• Deposits $100 = $58
• Now there's $58 in his account

The temperature at midnight was -11°C.

By midday, the temperature was 5°C.

What was the temperature change?

Steps to Solve

• Temperature changed from midnight to midday
• -11(midnight) + x = 5(midday)
• Add 11 to each side
• X = 16
• The temperature changed 16 degrees

You park in a garage 3 floors

below ground level. Then you get in the

elevator and go up 12 floors.
What floor do you get out on?

Steps to Solve

• 3 floors below ground level = -3
• Going up 12 floors = adding 12
• x = -3 + 12
• You exit on the 9th floor