L23 · Positive and negative numbers

1. 1.

   Theo is on a number line at 0 and moves 6 units left. What number is Theo on?

   Answer. −6

   Left of 0 is negative: −6.

2. 2.

   Nora is on a number line at 0 and moves 10 units left. What number is Nora on?

   Answer. −10

   Left of 0 is negative: −10.

3. 3.

   Jonah is on a number line at 0 and moves 5 units left. What number is Jonah on?

   Answer. −5

   Left of 0 is negative: −5.

4. 4.

   Priya is on a number line at 0 and moves 4 units left. What number is Priya on?

   Answer. −4

   Left of 0 is negative: −4.

5. 5.

   Write the opposite of 5. Then Mei needs 4 of that amount. What is the total they need?

   Answer. −20

   The opposite of 5 is −5. Then multiply by 4: −20.

6. 6.

   Luis is on a number line at 0 and moves 12 units left. What number is Luis on? Then Luis needs 2 of that amount. What is the total they need?

   Answer. −24

   Left of 0 is negative: −12. Then multiply by 2: −24.

7. 7.

   Theo is on a number line at 0 and moves 10 units left. What number is Theo on? Then Grace needs 4 of that amount. What is the total they need?

   Answer. −40

   Left of 0 is negative: −10. Then multiply by 4: −40.

8. 8.

   Theo is on a number line at 0 and moves 9 units left. What number is Theo on? Then Jonah needs 4 of that amount. What is the total they need?

   Answer. −36

   Left of 0 is negative: −9. Then multiply by 4: −36.

9. 9.

   Write the opposite of 5. Then Sam needs 5 of that amount. What is the total they need?

   Answer. −25

   The opposite of 5 is −5. Then multiply by 5: −25.

10. 10.

    Ava is on a number line at 0 and moves 12 units left. What number is Ava on? Then Malik needs 4 of that amount. What is the total they need?

    Answer. −48

    Left of 0 is negative: −12. Then multiply by 4: −48.

11. 11.

    Think

    Sam tried this problem:
    Write the opposite of 9.
    Sam wrote −8. That is not correct. What is the right answer?

    Answer. −9

    Sam’s answer −8 is off. The opposite of 9 is −9.

12. 12.

    Think

    Elena tried this problem:
    Theo is on a number line at 0 and moves 12 units left. What number is Theo on?
    Elena wrote −-12. That is not correct. What is the right answer?

    Answer. −12

    Elena’s answer −-12 is off. Left of 0 is negative: −12.

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