L7 · Addition with negative integers

1. 1.

   Use a number line: start at −4 and add −5. Where do you land?

   Answer. −9

   Adding a negative moves left: −4 + (−5) = −9.

2. 2.

   Use a number line: start at −9 and add −7. Where do you land?

   Answer. −16

   Adding a negative moves left: −9 + (−7) = −16.

3. 3.

   Use a number line: start at −4 and add −2. Where do you land?

   Answer. −6

   Adding a negative moves left: −4 + (−2) = −6.

4. 4.

   Use a number line: start at −2 and add −8. Where do you land?

   Answer. −10

   Adding a negative moves left: −2 + (−8) = −10.

5. 5.

   Use a number line: start at −5 and add −6. Where do you land? Then Theo needs 3 of that amount. What is the total they need?

   Answer. −33

   Adding a negative moves left: −5 + (−6) = −11. Then multiply by 3: −33.

6. 6.

   Use a number line: start at −4 and add −2. Where do you land? Then Ava needs 2 of that amount. What is the total they need?

   Answer. −12

   Adding a negative moves left: −4 + (−2) = −6. Then multiply by 2: −12.

7. 7.

   Use a number line: start at −2 and add −1. Where do you land? Then Luis needs 3 of that amount. What is the total they need?

   Answer. −9

   Adding a negative moves left: −2 + (−1) = −3. Then multiply by 3: −9.

8. 8.

   Use a number line: start at −3 and add −2. Where do you land? Then Priya needs 4 of that amount. What is the total they need?

   Answer. −20

   Adding a negative moves left: −3 + (−2) = −5. Then multiply by 4: −20.

9. 9.

   Use a number line: start at −5 and add −3. Where do you land? Then Theo needs 3 of that amount. What is the total they need?

   Answer. −24

   Adding a negative moves left: −5 + (−3) = −8. Then multiply by 3: −24.

10. 10.

    Use a number line: start at −2 and add −6. Where do you land? Then Priya needs 2 of that amount. What is the total they need?

    Answer. −16

    Adding a negative moves left: −2 + (−6) = −8. Then multiply by 2: −16.

11. 11.

    Think

    Sam tried this problem:
    Use a number line: start at −7 and add −3. Where do you land?
    Sam wrote −20. That is not correct. What is the right answer?

    Answer. −10

    Sam’s answer −20 is off. Adding a negative moves left: −7 + (−3) = −10.

12. 12.

    Think

    Elena tried this problem:
    Use a number line: start at −3 and add −1. Where do you land?
    Elena wrote −8. That is not correct. What is the right answer?

    Answer. −4

    Elena’s answer −8 is off. Adding a negative moves left: −3 + (−1) = −4.

Original extra practice. Keys are computed from the items, not guessed.