Example 1
Find −7 + 12.
- The signs are different, so subtract: 12 − 7 = 5.
- 12 is bigger, so the answer is positive.
Answer: 5
➕ Class 7 · Number system
Integers are the whole numbers and their negatives. The rules for signs look like a lot to remember, but they all come from the number line.
Notes
Chapter names and order differ by board and textbook edition, so follow your own textbook for the order.
Integers are ..., −3, −2, −1, 0, 1, 2, 3, ... Numbers to the right are greater. −2 is greater than −5 because it is further to the right.
Same signs: add the numbers and keep the sign, so −3 + (−4) = −7. Different signs: subtract the smaller from the larger and keep the sign of the larger, so −7 + 12 = 5.
Subtracting a number is the same as adding its opposite: 5 − (−8) = 5 + 8 = 13.
Same signs give a positive answer and different signs give a negative answer. (−6) × (−4) = 24 and (−48) ÷ 8 = −6.
Addition and multiplication are commutative and associative, and multiplying by 1 or adding 0 leaves a number unchanged. Division by zero is not defined.
Find −7 + 12.
Answer: 5
Find 5 − (−8).
Answer: 13
Find (−6) × (−4).
Answer: 24
Find (−48) ÷ 8.
Answer: −6
Avoid these
5 − (−8) is 13, not −3. Change the subtraction to addition of the opposite.
−5 − 3 = −8, because you move 3 more to the left of −5.
(−3)² = 9, but −3² means −(3²) = −9.
Try each question on paper first, then tap it to check your answer. The questions are generated by code and each answer is checked.
Answer: 6
Answer: 0
Answer: 6
Answer: 0
Answer: -4
Answer: -21
Answer: 90
Answer: -84
Answer: 21
Answer: 96
FAQ
Integers are the set of whole numbers and their negatives, including zero: ..., −2, −1, 0, 1, 2, ...
Multiplying by −1 flips a number to its opposite, and doing it twice gets you back to where you started.
Add the opposite: a − b = a + (−b).
Neither. Zero is an integer that is neither positive nor negative.
It covers the ideas taught in CBSE, ICSE and state-board maths. Chapter names and order differ by board and textbook edition, so follow your own textbook for the exact order.
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Adding and subtracting negative numbers (Grade 6): Adding and subtracting positive and negative whole numbers. Open the practice page or print a worksheet.