Adding & Subtracting Rational Numbers

When a person owes money on a credit card, the credit card holder can think of it as a negative balance.

Devin has a balance of –$9.50 on a credit card. Which two items can he purchase without his balance going below –$15.00?

• Cinnamon Bread and 2 Dinner Rolls

• Pizza Dough and Cinnamon Bread

• 12 Dinner Rolls

• Cinnamon Bread and 3 Dinner Rolls

An underwater camera is dropped from a helicopter flying 4.5 ft over the water. The camera has an elevation change of –8 feet. Where is the camera now in relation to the surface of the water?

The number line represents distance from sea level. What do positive numbers represent?                                     

The number line represents distance from sea level. What do negative numbers represent?

The number line represents distance from sea level. What does 0 represent?

Where is the camera after the change in elevation of –8 feet from the helicopter 4.5 ft. in the air?

(a)  

Carmela stands on the ground and kicks the ball 4.5 meters up into the air. It falls down and goes into another pit that is 3.5 meters deep. What is the total change in distance.

(a)  

Carmela stands on the ground and kicks the ball 4.5 meters up into the air. It falls down and goes into another pit that is 3.5 meters deep.

​ (a)   + 4.5 – ​ (b)   = –3.5

• 0
• 4.5
• -4.5
• -0
• 8
• -8

From an elevation of 2.5 feet above sea level, a bird dives 4 feet to catch a fish.   How far below the surface is the fish?

(a)  

Complete the equation to represent the situation.

2.5 – 4 = (a)