1. Unit 2. Day 8.

2. Please get out paper for today’s lesson
Name
Date
Period
Topic: Adding & Subtracting Rational Numbers
7.NS.A.2 Apply and extend previous understandings of multiplication and division and of fractions to multiply and divide rational numbers

3. 4th, 5th, & 6th grade

4. Example A: Add or subtract. Write in simplest form.
10 12
3 12 13 12
1 1 12 = + = 𝑜𝑟 6 4
5 6 10 12
1 4 3 12   : 6 , 12 , 18 , 24 , 30 , 36 , 42 , 48 , 54 , 60 , 66 , 72 , 78 : 4 , 8 , 12 , 16 , 20 , 24 , 28 , 32 , 36 , 40 , 44 , 48 , 52

5. Example B*: Add or subtract. Write in simplest form.
8 9 − 5 6
16 18
15 18 18 1 = − = 9 6
8 9 16 18
5 6 15 18   : 9 , 18 , 27 , 36 , 45 , 54 , 63 , 72 , 81 , 90 , 99 ,
108 ,
117 : 6 , 12 , 18 , 24 , 30 , 36 , 42 , 48 , 54 , 60 , 66 , 72

7. 7th grade

8. Example C:
5 14 − 5 8
20 56
35 56
−15 56
−1∙3∙5
− 15 56 = − = = = 14 8
2∙2∙2∙7
5 14 20 56
5 8 35 56   : 14 , 28 , 42 , 56 , 70 , 84 , 98 ,
112 ,
126 ,
140 ,
154 , : 8 , 16 , 24 , 32 , 40 , 48 , 56 , 64 , 72 ,

9. −
Example D:
− − 3 9
Example E:

10. Example D*: − −
−10 24
−1∙2∙5
−5 12 = = = = 8 24
2∙2∙2∙3
− 5 8
− 24 15
5 24 5 24   : 8 , 16 , 24 , 32 , 40 , 48 , 56 , 64 , 72 , 80 , 88 , 96 ,
104 : 24 , 48 , 72 , 96 ,
120 ,
144 ,
168 ,
192 ,
216 ,
240

11. : : : : Example E*: − 6 8 − 72 54  − 6 8 + − 3 9 − 13 12 −13 12 = = 8
− 72 54 
− − 3 9 +
− 54 72
− 24 72
−78
−1∙2∙3∙13
− 13 12
−13 12 = = 72 = = 8 9
2∙2∙2∙3∙3
− 3 9
− 72 24 
−1 1 12 : 8 , 16 , 24 , 32 , 40 , 48 , 56 , 64 , 72 , 80 : 9 , 18 , 27 , 36 , 45 , 54 , 63 , 72 +
− 1 3 +
− 3 4
− 12 9
− 3 4
− 6 8
− 3 9
− 9 12
− 13 12
−13 12
− 4 12 = =  4 3
− 1 3
− 12 4 
−1 1 12 : 4 , 8 , 12 , 16 , 20 , 24 : 3 , 6 , 9 , 12

12. 8 16 − 4 32 5 15 − 12 20 − 8 9 − − 5 6 Example F*: Example G*:
Example H*:

13. Example F: +
− 8 9 − − 5 6 −
− 1 18 = = 9 6
5 6 15 18
− 8 9
− 18 16   : 9 , 18 , 27 , 36 , 45 , 54 , 63 , 72 , 81 , 90 , 99 ,
108 ,
117 : 6 , 12 , 18 , 24 , 30 , 36 , 42 , 48 , 54 , 60 , 66 , 72

14. Example G*:
8 16 16 32 
8 16 − 4 32
16 32 − 4 32
12 32
2∙2∙3
3 8 = = = = 16 32
2∙2∙2∙2∙2
4 32 4 32  : 16 , 32 , 48 , 64 , 80 , 96 : 32 , 64 , 96 ,
128
1 2 − 1 8
1 2 4 8
4 8 − 1 8
3 8 = =  2 8 :
1 8 1 8 2 , 4 , 6 , 8 , 10 , 12  : 8 , 16 , 24 , 32

15. Example H*:
5 15 20 60 
5 15 − 12 20
20 60 − 36 60
−16
−4 15
−1∙2∙2∙2∙2 = = 60 = = 15 20
2∙2∙3∙5
12 20 36 60  : 15 , 30 , 45 , 60 , 75 , 90 : 20 , 40 , 60 , 80
5 15
1 3
9 15
3 5
1 3 5 15
5 15 − 9 15 −4 − = =  15 3 5
3 5 9 15  : 3 , 6 , 9 , 12 , 15 , 18 : 5 , 10 , 15 , 20