C Program to Compute Quotient and Remainder
C Program to Compute Quotient and Remainder
A school exercise asks you to quotient and remainder. Use small, named values first so you can distinguish the required calculation from the syntax used to express it.
Integer division truncates toward zero; the remainder satisfies dividend = quotient × divisor + remainder when the division result is representable.
Before this exercise, review operators and conversions and decisions and conditions. The worked program below applies those ideas to this specific problem.
Explain
Explain why quotient and remainder uses this sequence of operations.
Trace
Trace the sample values and predict the printed result.
Apply
Repeat the calculation with dividend -17.
Quotient and Remainder: follow the data
Given data
A school exercise asks you to quotient and remainder. Use small, named values first so you can distinguish the required calculation from the syntax used to express it.
Rule
Integer division truncates toward zero; the remainder satisfies dividend = quotient × divisor + remainder when the division result is representable.
Observed result
Quotient: 3; remainder: 2
Understand the operation
The quotient counts whole divisor-sized groups. The remainder is the part left after those groups, with the dividend’s sign when nonzero.
Read the declarations and operands before the output call. %d formats an int; floating-point results use an appropriate precision with %f. A format describes a value that was already computed—it does not choose the earlier arithmetic.
Read the complete C program
The input values are written into this complete C17 example so the calculation can be reproduced without an unavailable service. Change the named data, rebuild and compare the actual output with your prediction.
C17 · complete program
#include <stdio.h>
int main(void) {
int dividend = 17, divisor = 5;
printf("Quotient: %d; remainder: %d\n", dividend / divisor, dividend % divisor);
return 0;
}
Expected output
Quotient: 3; remainder: 2
Follow the values through the code
C17 · code used in this explanation
#include <stdio.h>
int main(void) {
int dividend = 17, divisor = 5;
printf("Quotient: %d; remainder: %d\n", dividend / divisor, dividend % divisor);
return 0;
}
17 / 5 produces three.
17 - 3 × 5 leaves two.
Follow the worked calculation
Start with the sample
17 / 5 produces three.
Apply the rule
17 - 3 × 5 leaves two.
Check the result
Quotient: 3; remainder: 2
Quotient: 3; remainder: 2
Try a small variation
C17 · code used in this explanation
#include <stdio.h>
int main(void) {
int dividend = 17, divisor = 5;
printf("Quotient: %d; remainder: %d\n", dividend / divisor, dividend % divisor);
return 0;
}
Repeat the calculation with dividend -17.
Worked answer
The worked answer follows the same rule with the requested changed data. Compare its complete source and output: Quotient: -3; remainder: -2. The result should follow from the operations, rather than from memorizing the first sample.
C17 · complete program
#include <stdio.h>
int main(void) {
int dividend = -17, divisor = 5;
printf("Quotient: %d; remainder: %d\n", dividend / divisor, dividend % divisor);
return 0;
}
Expected output
Quotient: -3; remainder: -2
Recognize the important boundaries
A zero divisor is invalid, and the minimum signed integer divided by -1 can be unrepresentable. Check these cases in a general signed division helper.
The demonstrated values stay within the types’ representable ranges. A program accepting arbitrary external values needs checked conversion and bounds before performing arithmetic.
Check your understanding
Choose the answer, then compare the reasoning for every option.
Use the idea independently
Integer division truncates toward zero; the remainder satisfies dividend = quotient × divisor + remainder when the division result is representable.
Continue with arithmetic operand types.
Continue with validated input.
Language reference: WG14 C11 committee draft. These examples use the C17-compatible subset of the explained language features.
Reaching the recap and completing the quizzes are separate milestones.