Adding and Subtracting Integers

Vocab

100

Absolute Value

The distance of a number from zero

200

Integer

The set of whole numbers and their opposites.

300

Opposite

The opposite of a number is the same distance from zero as the original number just on the other side.

400

|-6|

Absolute value of -6 = 6

500

6 and -6

Opposites

Adding Integers

100

Model with a number line

-5 + 9

4

200

Model with a number line

-12 + 5

-7

300

-16 + (-17)

-33

400

How do you find the sum of numbers with different signs

Subtract and take the sign of the bigger number

500

-16+18+-17

-15

Subtracting Integers

100

Change to addition and then model with counters

-4 - 6

-10

200

Change to addition and then model with counters

4 - 11

-7

300

Change to addition and then model with counters

15 - (-7)

22

400

Change to addition 

-27 - (-3)

-24

500

Change to addition

-10 - 11 - (-3)

-18

Mix

100

Change to addition

-2 - 3

-5

200

-10 + 30

20

300

Change to addition

21 - (+5)

16

400

Subtracting a negative is the same thing as...

Adding a positive

500

-10 + (-2) + (- 5)

-17

Word Problems

100

Kayla began a science experiment with 18 grams of an unknown solid. During the experiment, the change in the mass of the solid was – 7 grams. What was the mass of the solid at the end of the experiment? 

18 + (-7) = 25 grams

200

Clara and her family are vacationing in the Netherlands. They began a tour of the North Sea coastline at an elevation of  –8 feet. By the end of the tour, their elevation had decreased by 5 feet. What was their elevation at the end of the tour? 

-8 - 5

-8 + (-5) = -13 ft

300

The temperature on February 2 in Lake City was 14°F. The temperature in Ellenville the same day was –6°F. How much warmer was it in Lake City than in Ellenville? 

14 - (-6)

14 + 6 = 20°F

400

Bryant was playing the video game Ship, Ship Ahoy! He began Level 2 with 15 points but soon got –6 points because his character fell overboard. What is Bryant's total score now? 

15 + (–6) =9 points

  

500

The afternoon temperature in Biscoff Bay was –2°F. By midnight, a warm front moved in and the temperature rose to 11°F. What was the change in temperature from afternoon to midnight? 

11 – (–2) 

11 + 2 = 13°F