7th grade · Math · Unit 13 of 18
Multiply & Divide Signed Numbers
Sign rules
What your child practices
Multiplying and dividing positive and negative numbers (including fractions), using the sign rules, and real-world changes such as falling temperatures.
Alabama Course of Study content standard: 7.4 · multiplying and dividing rational numbers, including negative numbers
How we explain it
Children can open this short lesson before they practice.
- Multiply or divide the numbers as usual.
- Same signs give a positive answer.
- Different signs give a negative answer.
Example: What is −6 × 4? 6 × 4 = 24. Different signs: negative. Answer: −24
Multiply & Divide Signed Numbers in Alabama
In the Alabama Course of Study, this is unit 13 of 18 in 7th grade Math, after Mean, Median & Mode and before Proportional Relationships.
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
Without multiplying: is (−6) × 2 × (−6) positive or negative?
- Negative
- Positive
Positive
Hint: Count the negative factors. An even number of them gives a positive product; an odd number gives a negative one.
Question 2
What is 2 ÷ (−2)?
2 ÷ (−2) = ?
answer box
-1
Hint: Divide the sizes, then use the sign rule: same signs positive, different signs negative.
Question 3
The temperature falls 5 degrees every hour for 8 hours. What is the total change in temperature, in degrees? (Use a negative number for a fall.)
answer box
-40
Hint: 8 × (−5) = −40.
Question 4
What is 12 × (−9)?
12 × (−9) = ?
answer box
-108
Hint: Multiply the sizes, then use the sign rule: same signs positive, different signs negative.
Question 5
A change of −$4 is shared equally by 2 friends. What is each friend's change, in dollars?
answer box
-2
Hint: −4 ÷ 2 = −2.
Question 6
What is 1/3 × (−6)?
- -2
- -4
- 2
- -18
-2
Hint: 6 ÷ 3 = 2. One factor is negative, so the answer is negative.