7th grade · Math · Unit 1 of 20
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.
New York State Learning Standards learning standard: NY-7.NS.1 · 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 New York
In the New York State Learning Standards, this is unit 1 of 20 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
What is 19 + (-7)?
19 + (-7) = ?
- 26
- 12
- -12
- -26
12
Hint: Different signs: subtract the sizes, 19 − 7 = 12. Keep the sign of 19, the number farther from zero. The answer is 12.
Question 2
At 6 a.m. the temperature was -14°C. By noon it had risen 17°C. What was the temperature at noon?
🌡️-14°Canswer box°C
3 °C
Hint: Rising means adding: -14 + 17 = 3. On a thermometer, count up 17 degrees from -14.
Question 3
The high today was 7°C and the low was -6°C. How many degrees warmer was the high than the low?
answer box°C
13 °C
Hint: Find high − low: 7 − (-6) = 7 + 6 = 13. On the number line that's 6 steps from -6 up to 0, plus 7 more up to 7.
Question 4
Put these integers in order from least to greatest.
- -4
- 12
- -10
- -2
- 14
-10 → -4 → -2 → 12 → 14
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 -10 < -4. The least here is -10.
Question 5
Start at 1 and add (-2). Where do you land?
- -2
- 1
- -1
- 3
-1
Hint: Adding a negative number moves left. From 1, jump 2 to the left to land on -1.
Question 6
What is -6 − (-2)?
-6 − (-2) = ?
answer box
-4
Hint: Subtracting is the same as adding the opposite: -6 − (-2) = -6 + 2 = -4.