Unit 2. Day 5.

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)

Today’s Lesson Add/subtract: Mixed Numbers Add/Subtract: Decimals Add/subtract: Mixture of fractions/decimals

Example A: Add or subtract. Write in simplest form. 5 5 6 −7 1 2 5 5 6 7 1 2 35 6 − 45 6 − 5 3 35 6 15 2 −10 − 2∙5 − = = 6 = = 2∙3 6 2 −1 2 3 15 2 45 6 35 6 35 6   : 6 , 12 , 18 , 24 , 30 , 36 , 42 , 48 , 64 , 60 : 2 , 4 , 6 , 8 , 10 , 12 , 14 , 16 , 18 , 20

Example B*: Add or subtract. Write in simplest form. 6 3 5 −9 1 10 6 3 5 9 1 10 33 5 91 10 66 10 − 91 10 −25 − 5 2 −5∙5 − = = 10 = = 5 10 2∙5 −2 1 2 66 10 91 10 91 10 33 5   : 5 , 10 , 15 , 20 : 10 , 20

Today’s Lesson Add/subtract: Mixed Numbers Add/Subtract: Decimals Add/subtract: Mixture of fractions/decimals

Example C: + 5.8−8.7= − − 7 5 . 8 1 8 . 7 − − 8 . 7 5 . 8 2 . 9 2 . 9

Example D*: 1.8−7.5 1.89−7.5 Example E*: Example F*: −6.27−0.975

Example D*: + 1.8−7.5= − − 6 1 . 8 1 7 . 5 − − 7 . 5 1 . 8 5 . 7 5 . 7

Example E*: + 1.89−7.5= − − 1 6 4 1 . 8 9 1 7 . 5 − − 7 . 5 1 . 8 9 5 5 . 6 1 . 6 1 1 . 8 9 7 . 5 − − 7 . 5 1 . 8 9

Example F*: −6.27−0.975= − − − 1 1 1 1 6 . 2 7 0 . 9 7 5 + + 0 . 9 7 5 6 . 2 7 7 . 7.245 2 4 5 7 7.245 . 2 4 5

Example G*: −0.05−0.45 0.003+ −0.301 Example H*:

Example G: − −0.05−0.45= − − 1 1 0 . 0 5 0 . 4 5 0 . 4 5 0 . 0 5 + + 0.5 . 5 0.5 . 5

Example H*: + 0.003+ −0.301 = − − 2 9 1 0 . 3 0 1 1 0 . 0 0 3 − − 0 . 0 0 3 0 . 3 0 1 0.298 . 2 9 8

Example I*: Mr. Jordan did not realize his checking account had a balance of $200 when he used his debit card for a $317.25 purchase. What is his checking account balance after the purchase? − 317.25 = 200.00 − 117.25 317 . 2 5 200 . 0 0 − 1 1 7 . 2 5

Today’s Lesson Add/subtract: Mixed Numbers Add/Subtract: Decimals Add/subtract: Mixture of fractions/decimals

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: + +

−2.4 + 3 4 −2 1 2 3 4 − 2 1 2 Example --: −2.4 + 3 4 −2 1 2 3 4 − 2 1 2 −2.4 −2.4 Which way is better? − 24 10 3 4 − 5 2 + −2.4 + 0.75 −2.5 −2.5 − 20 48 20 15 − 20 50 + − −48+15−50 20 − −50 20 −33 1 1 3 1 1 2 . 4 1 . 6 5 − 0 . 7 5 + 2 . 5 −4 3 20 −83 1 1 . 6 5 . 6 5 . 20 = 4 4.15 1 5

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

Example -: In my opinion, fractions are preferable … as this problem demonstrates. −0.8 + 2 3 2 3 −0.8 −0.8 + 0.6666666666666… − 7 1 0 . 8 −2 15 − = 0 . 6 7 0 . 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 −0.1 3 0.13 . 1 3

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

Groups

−5.2− −3.1 +5.2 Example K: Example L: Example M: Example N: 32 + −12 7 8 Example L: 3 1 6 +20.3 − −5 5 6 Example M: 16 20 − −1.8 − 4 5 Example N: S.51 Exercise 2

+ Example K*: −5.2− −3.1 +5.2 3.1

Example L*: 32 + −12 7 8 −12 7 8 32 32 1 − 103 8 8 256 − 8 103 256−103 8 153 8 19 1 8 =

+ + 9 29.3 + + Example M*: 3 1 6 +20.3 − −5 5 6 3 1 6 +20.3 − −5 5 6 3 1 6 +20.3 − −5 5 6 3 1 6 +20.3 − −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 95+609+175 30 9 + 879 30 293 10 29 3 10 = = = 29.3 29.3

Example N*: + 16 20 − −1.8 − 4 5 16 20 − 4 5 1.8 4 5 4 5 + 18 10 − 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 = =