Then remove 2 sets of=4 negative counters
from the mat. There are
8 positive counters
remaining.So, - 2 ×(-4) = 8.You can model division by separating algebra counters into equal-size groups.Model - 9 ÷3 using algebra counters.Place 9 negative counters on the mat torepresent -9.Separate the counters into 3 equal-size
groups. There are 3 negative counters in
each of the three groups.So, - 9 ÷ 3 = -3.and Apply
Find each product. Use models if needed.- 7 × (-2) 2. 2 × (-3) 3. 4 × (-4) 4. 8 × (-1)
- 5 × (-1) 6. - 2 × (-2) 7. - 4 × (-3) 8. - 6 × (-2)
Find each quotient. Use models if needed.
- 12 ÷ 4 10. - 18 ÷ 9 11. - 20 ÷ 5 12. - 10 ÷ 2
- 6 ÷ 6 14. - 14 ÷ 7 15. - 16 ÷ 4 16. - 8 ÷ 2
the Results
- How are the operations - 5 × 4 and 4 × (-5) the same? How do they differ?
- MAKE A CONJECTURE Write a rule you can use to find the sign of the product
of two integers given the sign of both factors. Justify your rule. - When the dividend is negative and the divisor is positive, is the quotient
positive or negative? How does this compare to a multiplication problem
when one factor is positive and one is negative? - MAKE A CONJECTURE Write a rule you can use to find the sign of the quotient
of two integers. Justify your rule.
Lesson 3B Multiply and Divide Integers 103102_113_C2L3_895130.indd 103 12/29/09 12:50 PM