EXAM 2
Math 365_503
Oct. 29, 1999

Name SSN

Part I. Select the best answer for each question. You may write a statement in support of your answer if so desire.

1. (2 pts) If r and s are integers such that r=-s
   then r is the additive inverse of s. TrueFalse
   
2. (2 pts) The number 0 is the multiplicative identity for the integers. TrueFalse
   
3. (2 pts) If s is an integer then -s<s. TrueFalse
   
4. (3 pts) Which of the following operations do NOT have the closure property in the set of integers?
   a.addition b. multiplication
   c.subtraction d. division \
5. (3 pts) If x+y is a whole number then
   a.y+x is a whole number. b. is a whole number.
   c. x-y is a whole number. d. Both x and y are whole numbers.
6. (3 pts) Which of the following statements are true for any whole numbers e, f and g?
   a.(e-f)-g=e-(f-g)b.
   c.(ef)g=e(fg) d.

Part II. Answer each question. For full credit, show work necessary to arrive at your answer.

1. (6 pts) Subtract from .
2. Write in
   1. (4 pts) Egyptian notation:
   2. (4 pts) Roman notation:

3. (5 pts) Write as a base five number.
   
   
4. (5 pts) Write as a base seven number.
   
   
5. (8 pts) Solve using an instructional algorithm. (You should know two such algorithms, choose one and use it.)
6. (8 pts) Solve using an instructional algorithm. (The numbers are in base ten.)

7. (8 pts) Solve using an instructional algorithm. (The numbers are in base ten.)
8. (8 pts) Multiply and together. The answer must be a base seven number. You may use any method.

Part III. Answer the following questions as completely as possible.

1. (10 pts) Draw a sketch using either mats and strips OR place value cards describing the problem .

2. 1. (5 pts) Write a word problem which would use the equation (10-3)+5 in its solution.
   2. (5 pts) Draw a representation of this equation (using either a number line or colored markers).

3. (10 pts) Explain why (-a)(-b) is equal to ab.

• About this document ...