Chapter 2.2

Adding positive and negative numbers

THS Algebra I

Warm – Up

Find the sums without calculators.

868 + 75 =

Find differences without calculators

401 – 83 =

5 1

7 2

5 3

6 10

Warm – Up Answers

Find the sums without calculators.

868+ 75945

Find differences without calculators 401– 83 318

5 1 10 7

7 2 14 14

5 3 25 9

6 10 30 30

1 1 17 3

114 14

16 8

30 15

93 10 11

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Yesterday’s HW answers

7) > 8)> 9)=13) -418 19)32 22)-16 ½

25) 17 26)100 29)13 ½

30) 3/5 45) 6 46) – 2/5

47) 16 48) 7/8

1)50 2)56 4)162 9)8 ½ 11)15 ½

13) 33 16) 30 19) 4(5-3)+2=1024) 6/3 + 3(5) = 17

27) (3+6)/5=12/5 OR 1.8

1) 6,12,18,24,30,363) 27,33,39,45,51,5713) 315) 2

Add positive and negative numbers

Let’s use different colored buttons to show

-7 + (+4)

How do 7 red buttons match up with 4 ?

How many remain? 3 positive or 3 negatives?

-7 + (+4) = 3 negatives

Add positive and negative numbers

6 4 6 8

2 ( 4) 5 ( 8)

2 7 4 ( 7)

Add positive and negative numbers

6 4 10 6 8 2

2 ( 4) 2 5 ( 8) 3

2 7 9 4 ( 7) 3

Go Tigers THS