Rewrite subtractions, then solve left to right
7. \(8 - (-5) - 6\)
Step 1 (Rewrite):
Step 2 (Combine):
Final Value:
8. \(-12 - 4 - (-9)\)
Step 1 (Rewrite):
Step 2 (Combine):
Final Value:
9. \(-7 - (-11) - 15\)
Step 1 (Rewrite):
Step 2 (Combine):
Final Value:
10. \(14 - (-6) - (-10)\)
Step 1 (Rewrite):
Step 2 (Combine):
Final Value:
Opposite Shift Math Unit • Grade 7 Mathematics Page 2 of 3
Page 3 of 3
At-Bat 3
Show every intermediate stage
11. \(-10 - (-6) - 8 + (-3)\)
Step 1: Convert all subtractions into addition:
Step 2: Combine terms left-to-right or group by sign:
Final Solution:
12. \(14 - 19 - (-5) - (-8)\)
Step 1: Convert all subtractions into addition:
Step 2: Combine terms left-to-right or group by sign:
Final Solution:
13. \(-7 + (-12) - (-15) - 9\)
Step 1: Convert all subtractions into addition:
Step 2: Combine terms left-to-right or group by sign:
Final Solution:
14. \(-25 - (-30) - 14 - (-9)\)
Step 1: Convert all subtractions into addition:
Step 2: Combine terms left-to-right or group by sign:
Final Solution:
Real-World Application: Elevation Difference Write an expression & evaluate
15. Death Valley Elevation Difference: Badwater Basin in Death Valley sits at \(-282\text{ ft}\) below sea level. Telescope Peak overlooks it at \(11,049\text{ ft}\) above sea level. Write a subtraction expression to calculate the vertical elevation difference between the peak and the basin, rewrite it as addition, and solve.
Subtraction Expression:
Rewrite as Addition:
Total Elevation Difference:
Turn in this packet and grab the standalone Opposite Shift Exit Ticket (4 fluency problems + 1 open-ended conceptual response).
Separate Slip
Opposite Shift Math Unit • Grade 7 Mathematics Page 3 of 3
Support: Provide vertical thermometer / number line desk strips. Have students physically highlight the subtraction sign and the number immediately following it.
Extension: Challenge students to create a 5-term expression that evaluates to zero using at least three subtractions.
Opposite Shift Teacher Guide • Grade 7 Mathematics Page 1 of 2
Master Key & Solutions
Opposite Shift • Grade 7
1. \(8 + (-3) = \mathbf{5}\)
2. \(-7 + (-4) = \mathbf{-11}\)
3. \(-6 + 11 = \mathbf{5}\)
4. \(-14 + 14 = \mathbf{0}\)
5. \(-15 + (-8) = \mathbf{-23}\)
6. \(12 + (-19) = \mathbf{-7}\)
7. \(-9 + 0 = \mathbf{-9}\)
8. \(-22 + 30 = \mathbf{8}\)
9. \(16 + (-7) = \mathbf{9}\)
10. \(-13 + (-13) = \mathbf{-26}\)
11. \(-25 + 18 = \mathbf{-7}\)
12. \(0 + (-34) = \mathbf{-34}\)
1. \(9 + (-14) = \mathbf{-5}\)
2. \(5 + 8 = \mathbf{13}\)
3. \(-7 + (-6) = \mathbf{-13}\)
4. \(-11 + 4 = \mathbf{-7}\)
5. \(-16 + 16 = \mathbf{0}\)
6. \(-24 + 35 = \mathbf{11}\)
7. \(8 + 5 + (-6) = 13 + (-6) = \mathbf{7}\)
8. \(-12 + (-4) + 9 = -16 + 9 = \mathbf{-7}\)
9. \(-7 + 11 + (-15) = 4 + (-15) = \mathbf{-11}\)
10. \(14 + 6 + 10 = 20 + 10 = \mathbf{30}\)
11. \(-10 + 6 + (-8) + (-3) = -4 + (-8) + (-3) = \mathbf{-15}\)
12. \(14 + (-19) + 5 + 8 = -5 + 5 + 8 = \mathbf{8}\)
13. \(-7 + (-12) + 15 + (-9) = -19 + 15 + (-9) = \mathbf{-13}\)
14. \(-25 + 30 + (-14) + 9 = 5 + (-14) + 9 = \mathbf{0}\)
15. Elevation Problem: \(11,049 - (-282) = 11,049 + 282 = \mathbf{11,331\text{ ft}}\).
Exit Ticket Key
1. \(14 - (-8)\)
Rewrite: \(14 + 8\)
Answer: 22
2. \(-18 - 9\)
Rewrite: \(-18 + (-9)\)
Answer: -27
3. \(-11 - (-16)\)
Rewrite: \(-11 + 16\)
Answer: 5
4. \(-5 - (-12) - 8\)
Rewrite: \(-5 + 12 + (-8)\)
Answer: -1
5. Open-Ended Justification Rubric: Correct Value: \(10 - (-4) = \mathbf{14}\)
• Claim: Marcus is Incorrect (0.5 pt).
• Conceptual Explanation (0.5 pt): Award full credit if student explains that subtracting a negative means adding its opposite (\(+4\)), that removing debt makes total balance increase, or that on a number line subtracting points left but a negative reverses direction to the right, landing on \(14\).
Opposite Shift Teacher Guide • Grade 7 Mathematics Page 2 of 2
