Assessment Tool

Lecture 4: Arithmetic Expressions

Content Tested: Int and Double Types, Arithmetic in C

Lecture Content:

Arithmetic expressions
Integer and floating-point (double) types
Unary and binary operators
Precedence
Associativity
Conversions and casts
Symbolic constants

Goals:

Understand associativity and precedence rules
Understand arithmetic on int and double types in C

Assessment Technique: Expression Exercises

Purpose:

This activity allows instructors to see if students understand how to simplify arithmetic expressions in C.

Activity:

Simplify the following expressions (remember, these expressions are written in the C language and may not follow conventional mathematical rules):

1. (15 / 2) * (3 / 2)
2. 15 * 3 / 2 / 2
3. 3 / 2 * 15 / 2
4. 15 / 2 * 3 / 2
5. (15 * 3)/(2 * 2)
6. (15.0 * 3) / 2
7. (int) (15.0 / 2.0)
8. 8 + 7 % 5 - 6
9. 6 - -3 * 50 % (48 + 9 / 8)
10. (double) 10 / 4
11. (double) (10 / 4)
12. (int) ((double) 10) / (double) 4 + 1.0

Solutions:

1. 7
2. 11
3. 7
4. 10
5. 11
6. 22.5
7. 7
8. 4
9. 9
10. 2.5
11. 2.0
12. 3.0 (The integer 2 is added to 1.0, so the result is a double.)

Possible Uses of Activity:

Have students work in groups to complete this activity. The instructor may want to circulate throughout the groups to ensure that each group is making progress. After the groups have completed the problems, the instructor can ask for volunteers for each problem. Be sure to ask for explanations of the arithmetic.
Have students work individually on their problems and form a small group to discuss their answers.