Algebra 1 Notes
Chapter 2 Section 1 Part 1:
Adding Rational Numbers
2 + 6 = ­10 ­9
­8 ­7
­6
­5 ­4
­3
­2
­1
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
4 + (­6) = ­10 ­9
­8 ­7
­6
­5 ­4
­3
­2
­1
­3 + (­5) = ­10 ­9
­8 ­7
­6
­5 ­4
­3
­2
­1
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12
6
0
­6
­12
Rules For Adding Integers:
Rules For Adding Integers:
Problem
Pos/Neg
Sum/Difference Answer Pos + Pos
Sum
Positive
Neg + Neg
Sum
Negative
Pos + Neg
Difference
Neg + Pos
Difference
Sign of the larger
integer
Sign of the larger integer
Adding Integers Without A
Number LIne:
­5 + (­6) =
3.4 + 9.7 =
13 + (­34) =
­3 + (­1) = 4
2
Let's try some!!
Adding Integers Without A
Number Line:
­7 + (­4) = ­11
Now You!
­1.5 + 3.4 = 1.9
8 + (­5) = 1
9
6 18
1. A football team gains 2 yards and loses 7 yards in two
plays. Use addition to find the result of the two plays
(how many yards did the team gain or lose total?)
2. The temperature falls 15 degrees and then rises 18
degrees. Use addition to find the change in the
temperature.
3. The temperature at 5:00 A.M. is -38 F. The temperature rises
20 by 11:00 A.M. Use addition to find the temperature at 11:00
A.M.
4. A football team has possession of the ball on their own 15-yd
line. The next two plays result in a loss of 7 yds and a gain of 3
yds respectively. On what yard line is the ball after the two
plays?
See if you can do this problem,
using what you know so far:
Evaluate -n + 8.9 for n = -2.3
More Examples??
Yes
No
Evaluate each expression for t = -7.1
t + (‐4.3) 8.5 + (‐t)
‐2 + t ‐t + 7.49