1. Unit 2. Day 10.

2. Please get out paper for today’s lesson
Name
Date
Period
Topic: Adding & Subtracting Rational Numbers
7.NS.A.1 Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers (fractions)

3. Q: What is a rational number?
A: A number that can be written as a fraction 𝑝 𝑞
− 5 7
− 5 7
2 3
2 3
−4 5 6
−4 5 6
0.875
0.875
−16. 3
−16. 3
Today: + +

4. − −2 1 2
3 4
− 2 1 2
Example A:
− −2 1 2
3 4
− 2 1 2
−2.4
−2.4
− 24 10
3 4
− 5 2 +
−2.4 +
0.75
−2.5
−2.5
− 20 48 20 15
− 20 50 + −
−48+15−50 20 −
−33 1
−50 20 1 3 1 1
2 . 4 − +
2 . 5
−4 3 20
−83 = 1 . 6 5 . 20 4
4.15 1 5

5. Which way is better?

6. −
2 3
Example -:
−0.8
− 8 10
2 3 +
− 30 24 30 20 + − −4
−2 15 = 30 =

7. Example -: −
2 3
−0.8
−0.8 + … − 7 1
0 . 8
−2 15 − =
−0.1 3
0.13 . 1 3

8. Example B*: +
− − −2 5 6
−1 1 6
2 5 6
4.5
− 7 6
45 10
17 6 + +
− 30 35 30
135 85 30 + + −
6 1 6
37 6
185
100 = = 30 =

9. Groups

10. −5.2− −3.1 +5.2 Example C: Example D: Example E: Example F:
32 + −12 7 8
Example D:
− −5 5 6
Example E:
16 20 − −1.8 − 4 5
Example F:
S.51 Exercise 2

11. +
Example C:
−5.2− −
3.1

12. Example D*:
32 + −12 7 8
−12 7 8 32
32 1
− 103 8 8
256
− 8
103
256−103 8
153 8 =

13. + + 9 29.3 + + Example E*: 3 1 6 +20.3 − −5 5 6 3 1 6 +20.3 − −5 5 6
− −5 5 6
− −5 5 6
3 1 6
5 5 6
3 1 6
5 5 6
20.3
20.3
19 6
203 10
35 6 + +
19 6
35 6 + 30 95 30
609
175 30 + + 6 54 9 +
879 30 = = =
29.3
29.3

14. Example F: +
16 20 − −1.8 − 4 5
16 20
− 4 5
1.8
4 5
− 4 5
18 10
− 4 5
18 10 + 10 8 18 −8 10 10 + +
9 5
1.8
8+18−8 10
1 4 5 26
−8 10
9 5
1 4 5 18 = 10 = =