Activity 12– INTEGERS –MULTIPLICATION/DIVISION
EXERCISES
MULTIPLICATION
Using counters to model the integer multiplication –3(-5):
Using the charged field to model the integer multiplication –2(-6):
Use the number line to model - 6 (- 5).
Use a calculator to find - 34 (- 435).
Formulate procedures for multiplying integers.
Is the set of integers closed under multiplication?
State the multiplicative identity for the set of integers.
Does – 24 have a multiplicative inverse in the set of integers?.
Is integer multiplication Commutative? Associative? Distributive over addition?
Distributive over subtraction?
10. State the zero property of multiplication.
11. Fill in the blank without parentheses :  (4  a)  _________
1.
2.
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5.
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9.
DIVISION
You might think of a  b , with b  0 , as finding a number c so that c  b  a.
12. Find  39 13 .
13. Formulate procedures for dividing integers.
14. Use a calculator to find  345  15 .
15. Is division of integers commutative? Give a counterexample if not.
16. Is division of integers associative? Give a counterexample if not.
Properties of integer division : For all integers a and b, a  0
a) a  a  1
b) a 1  a
c) 0  a  0
d) ab  a  b
e) Division by zero is not uniquely defined and hence we do not divide by zero.