7th grade · Math · Unit 13 of 17
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.
Washington State Learning Standards learning standard: M.7.Q.NS.2 · multiplying and dividing rational numbers, including negative numbers, and solving real-world problems with them
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
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 1 × (−2) × (−3) positive or negative?
- Positive
- Negative
Positive
Hint: Count the negative factors. An even number of them gives a positive product; an odd number gives a negative one.
Question 2
A change of −$24 is shared equally by 4 friends. What is each friend's change, in dollars?
answer box
-6
Hint: −24 ÷ 4 = −6.
Question 3
What is −1 × (−6)?
−1 × (−6) = ?
answer box
6
Hint: Multiply the sizes, then use the sign rule: same signs positive, different signs negative.
Question 4
The temperature falls 5 degrees every hour for 7 hours. What is the total change in temperature, in degrees? (Use a negative number for a fall.)
answer box
-35
Hint: 7 × (−5) = −35.
Question 5
What is −1/5 × 25?
- -4
- -7
- 5
- -5
-5
Hint: 25 ÷ 5 = 5. One factor is negative, so the answer is negative.
Question 6
What is 48 ÷ (−6)?
48 ÷ (−6) = ?
answer box
-8
Hint: Divide the sizes, then use the sign rule: same signs positive, different signs negative.