Mathematical functions (ROUND, CEIL, FLOOR, ABS) in PostgreSQL - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Output of ROUND function with decimal places

What is the output of this SQL query?

SELECT ROUND(12.3456, 2);

PostgreSQL

SELECT ROUND(12.3456, 2);

A 12

B 12.34

C 12.35

D 13

💡 Hint

ROUND rounds the number to the specified decimal places.

ROUND(12.3456, 2) rounds the number to 2 decimal places, resulting in 12.35.

❓ query_result

intermediate

Output of CEIL function on negative decimal

What is the output of this SQL query?

SELECT CEIL(-3.7);

PostgreSQL

SELECT CEIL(-3.7);

A -3

B -4

C -3.7

D 3

💡 Hint

CEIL returns the smallest integer greater than or equal to the number.

CEIL(-3.7) returns -3 because -3 is the smallest integer greater than or equal to -3.7.

❓ query_result

advanced

Output of FLOOR function with positive decimal

What is the output of this SQL query?

SELECT FLOOR(7.999);

PostgreSQL

SELECT FLOOR(7.999);

A 8

B 7

C 7.999

D 0

💡 Hint

FLOOR returns the largest integer less than or equal to the number.

FLOOR(7.999) returns 7 because 7 is the largest integer less than or equal to 7.999.

❓ query_result

advanced

Output of ABS function on negative integer

What is the output of this SQL query?

SELECT ABS(-15);

PostgreSQL

SELECT ABS(-15);

A 15

B 0

C -15

D NULL

💡 Hint

ABS returns the absolute value of the number.

ABS(-15) returns 15 because absolute value removes the negative sign.

🧠 Conceptual

expert

Understanding combined use of ROUND, CEIL, FLOOR, and ABS

Given the query:

SELECT ROUND(CEIL(-2.3) + FLOOR(3.7) + ABS(-4.5), 0);

What is the output?

PostgreSQL

SELECT ROUND(CEIL(-2.3) + FLOOR(3.7) + ABS(-4.5), 0);

A 7

B 5

C -6

D 6

💡 Hint

Calculate each function step-by-step before adding and rounding.

CEIL(-2.3) = -2, FLOOR(3.7) = 3, ABS(-4.5) = 4.5; sum = -2 + 3 + 4.5 = 5.5; ROUND(5.5,0) = 6.