7th grade · Math · Unit 1 of 18
Add & Subtract Integers
Positives, negatives and zero pairs
What your child practices
Adding and subtracting positive and negative numbers with number lines, temperatures and elevations, including the idea that subtracting a number is the same as adding its opposite.
Alabama Course of Study content standard: 7.4 · adding and subtracting rational numbers, including negative numbers
How we explain it
Children can open this short lesson before they practice.
- On a number line, adding moves right and subtracting moves left.
- A positive and a negative of the same size cancel out: +1 and −1 make 0.
- Subtracting a negative is the same as adding a positive.
Example: −3 + 5 = ? Start at −3 on the number line. Move 5 to the right: −2, −1, 0, 1, 2. Answer: 2
Add & Subtract Integers in Alabama
In the Alabama Course of Study, this is unit 1 of 18 in 7th grade Math, before Decimal Operations.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Which expression has the same value as -14 − (-2)?
- -14 + (-2)
- -14 + 2
- 14 + (-2)
- -2 − (-14)
-14 + 2
Hint: Subtracting a number is the same as adding its opposite. The opposite of -2 is 2, so -14 − (-2) = -14 + 2 = -12.
Question 2
Maya is scuba diving at -16 m (below the surface). Maya swims up 8 m, then down 15 m. What integer gives Maya's new position?
answer boxm
-23 m
Hint: Up is + and down is −: -16 + 8 − 15 = -23. Work left to right.
Question 3
Put these integers in order from least to greatest.
- -2
- -5
- -18
- -10
- 16
-18 → -10 → -5 → -2 → 16
Hint: Picture a number line: the farther left, the less. Every negative is less than zero, and a negative farther from zero is less, so -18 < -10. The least here is -18.
Question 4
At 6 a.m. the temperature was -7°C. By noon it had risen 24°C. What was the temperature at noon?
🌡️-7°Canswer box°C
17 °C
Hint: Rising means adding: -7 + 24 = 17. On a thermometer, count up 24 degrees from -7.
Question 5
Start at 1 and add 2. Where do you land?
- 4
- -1
- 3
- -3
3
Hint: Adding a positive number moves right. From 1, jump 2 to the right to land on 3.
Question 6
What is -20 − 8?
-20 − 8 = ?
answer box
-28
Hint: Subtracting is the same as adding the opposite: -20 − 8 = -20 + (-8) = -28.