V. Practice: Use a Number Line or Algebra Tiles, if you need it!

20. -5+-4= O] 21. 7 + --4= ÿ 22. 18 + -- 3 = -- } I

e e ÿ# #G# #° ' OO o,

#, 0

25. 0+-4=--ÿ

0ÿ

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26. -2+8+-4=

°'/

o °t£_ÿ

27. -3+-4= - 7

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29. 11+12= 2:ÿ

o oo 000o0o 6012oo o booOo ooo

30. -9 +-1o = -Iÿ

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# P J#4 r

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31. -7+3=

# 0

NAME DATE

Study Guide and InterventionAdding integers

PERIOD

For integers with the same sign:• the sum of two positive integers is positive.• the sum of two negative integers is negative.

For integers with different signs, subtract their absolute values, The sum is:• positive if the positive integer has the greater absolute value.• negative if the negative integer has the greater absolute value.

To add integers, it is helpful to use counters or a number line.

Find 4 + (-6).

Method 1 Use counters,Combine a set of 4 positive countersand a set of 6 negative counters on a mat,

Method 2 Use a number line.• Stalÿ at 0,• Move 4 units right.• Then move 6 tmits left.

®®®®O0O@O0

@04 + (-6) 4 + (-6) ==-2

-4,

-1=,.

l -6"I ÿ1 I

i +,,. 'riI I I I I I , ',-3-2-1 0 1 2 3 4 5

4 + (-6) ==-2

',J \ s u_ÿ_ÿ.'ÿ -ÿ

Add.

1.-5+(-2): -7 2. 8+1 = o[

Iÿ,-\\4. 16 + (-11) ÿ ÿ- 5. -22 + (-7) =- ÿ 2

3. -7 + 10 -

6. -50+50 = D

7. -10 + (-10) : -2.0 8. 100 + (-25) = "75- 9. -35 + -20 = "- ÿ._,q'-

Evaluate each expression if a = 8, b = -8, and e = 4.

10. a + 15 11. b + (-9)

13. b+c 14. -10 +c

12. a +4- =(b

15. 12 + b

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8kÿ

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-7

NAME DATE PERIOD

PracticeAdding Integers

Add.

1. 34+22 ÿ- ÿ-ÿ, 2. -29+30 - I 3.9+(-32) = - P. 5

4 16 + (-2s)- -ÿ ÿr 5. 4 + (-50) : - urÿ 6. -12+(-63) - ---75"

7. -42+42 ÿ- D 8. -28 + 14 = - }L]L 9. 13+63 -ÿ ÿ

10. 18+(-12)+5 " \\ 11. -22+(-10)+15 12. -14 +0+ 13 -- - [23-12 = - 3z 4-ÿs-=-!7

Write an additionÿgxpressioÿ to describe each situation. Then findeach sum and explain its meaning.

13. WEIGHT An actor gains 20 pounds for a part and then loses 15 9oundsduring the filming of a movie to go along with the storÿ

14. TEMPERATURE At 4:00 A,M., the outside temperature was -28°F, By 4:00P,M, that same day, it roseÿ5ÿ38 degrees.14 Lÿ i) rÿ -ÿ5 ÿ--ÿ ÿ_ÿr o-ÿ--ÿ-ÿ-ÿ% 4-ÿ Iÿ0¢<% I0 Aÿ_ÿrÿs mJoÿv-e_ ÿ:5.

J-to

ALGEBRA Evaluate each expression if a = 12, b = -15, and c = -i0.

15. a + (-12). 16. -20 + b 17. c + 23

II - t'7.- - ao ÿ;S-

18. b +c 19. a+c 20. a+b

\

21. ROLLER COASTERS The latest thrill ride at a popular theme park takesroller coaster "ÿms_on an exciting ÿde. In the first 20 seconds, it carries itspassengers 6 a 100ÿ- eÿer hill, phmges them ÿeters, andquickly takes them back ÿeter rise. How much higher or lowerfrom the starÿ of the ride are they after these 20 seconds?

27+ÿ?

2-4 Enrichment

Adding a List of IntegersWhen you need to add a list of integers, sometimes it can be helpful to reorderthe list of integers so you first add all the positive inte£ers, -and then all thenegative integers.

Marcy is studying weather conditions for herscience fair project. Dmÿing one 24-hourperiod, she recorded the changes in airtemperature in the table at right. If the airtemperature was 76°F at the start of herobservations, what was the air temperature24 hours later?

Time02:0004:0006:0008:0010:0012:00

Change inTemp. (°F)

-1-2

+2+4+4+3

Time.14:0016:0018:0020:0022:0000:00

iA--9

Change inTemp. (°F)

-16

+2+1+3-1-2

First add all the positive changes in air temperature and then all the ÿ 5W(g- % C_.-ÿ g C

negative changes in air temperature. ÿ 0ÿ2t:- e_fA_ÿ& Oÿe 5L7,ÿ((+2) + (+4) + (+4) + (+3) + (+2) + (+1)+ (+8) = +19

Yÿ" gÿ ÿ(-1)+ (-2)" + (-16) + ('-1) + (-2)= -22 y0(.£ bÿ)l(ÿ aug`-- "/'k-Ac3ÿ'ÿLÿ- 19e

temperature. 5 (A- ÿ g ÿ{)bg ]¢b ÿ.ÿ Next add the results to find the overall change and the new ÿ& L55 CLfÿ/vÿ Vv0 .Qvÿ/{ +19+(-22)=-3 ÿ 76ÿ+(-3°)=73°F ,)

1. The passenger elevator in the Empire State Building registered thefollowing journey log between 9:00 A.ÿa. and 9:15 A.M, on a Mondaymorning. At which floor was the elevator at 9:15 A.M. if it started in theLobby, which is Floor 1?

of floors 1" 17 ÿ 21 ÿ 16 $ 3 ÿ 4 ÿ 11

2. A deep-sea diver attached to a safely cable was lowezÿd into the water to a - tÿ o L) - zÿodepth of 600 feet. Dinting the next hour, the safety cable was let out 250 feet, - ÿ 3 ÿ- W tpulled in 36 feet, pulled in 69ÿfÿt, let out 23 feet, pulled in 51 feet, let out 68 ÿ ,feet, and pulled in 24 ÿ-to allow the diver to exploÿnd of the hotu, °mzr" ÿoc>

what was the depth of the diver? - ÿ "} Z ÿ- 18 o -ÿ

+7-'4;-

Gain3. The Franklin Wildcats football team was competing in

the regdonal championship game, The offense had theball at the 50-yard line as they tried to score to win thegame. Their progn'ess during each play was as follows.

gain 0, gai(.ÿ, lose 2, lose 1ÿÿ

On. what yard line did the Wildcats end?

5* - O-1

4- *4{0