ROUND, CEIL, FLOOR in MySQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to round the value 3.7 to the nearest whole number.

MySQL

SELECT [1](3.7);

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ATRUNCATE

BCEIL

CFLOOR

DROUND

Attempts:

3 left

💡 Hint

Common Mistakes

Using CEIL or FLOOR instead of ROUND when the goal is nearest rounding.

The ROUND function rounds a number to the nearest integer. Here, 3.7 rounds to 4.

2fill in blank

medium

Complete the code to get the smallest integer greater than or equal to 5.2.

MySQL

SELECT [1](5.2);

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AFLOOR

BROUND

CCEIL

DTRUNCATE

Attempts:

3 left

💡 Hint

Common Mistakes

Using FLOOR instead of CEIL, which rounds down.

The CEIL function returns the smallest integer greater than or equal to the number. CEIL(5.2) returns 6.

3fill in blank

hard

Fix the error in the code to get the largest integer less than or equal to 7.9.

MySQL

SELECT [1](7.9);

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AFLOOR

BCEIL

CROUND

DTRUNCATE

Attempts:

3 left

💡 Hint

Common Mistakes

Using CEIL instead of FLOOR, which rounds up.

The FLOOR function returns the largest integer less than or equal to the number. FLOOR(7.9) returns 7.

4fill in blank

hard

Fill both blanks to round 4.567 to 2 decimal places and then get the ceiling of the result.

MySQL

SELECT CEIL([1](4.567, [2]));

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AROUND

BCEIL

C2

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using CEIL inside CEIL or wrong decimal places.

First, ROUND(4.567, 2) rounds the number to 4.57. Then, CEIL(4.57) returns 5.

5fill in blank

hard

Fill all three blanks to get the floor of 9.876 after rounding it to 1 decimal place.

MySQL

SELECT [1]([2](9.876, [3]));

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AFLOOR

BROUND

C1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up FLOOR and CEIL or wrong decimal places.

First, ROUND(9.876, 1) rounds to 9.9. Then, FLOOR(9.9) returns 9.

Practice

1. Which MySQL function rounds a number to the nearest whole number or specified decimal place?

easy

A. CEIL

B. ROUND

C. FLOOR

D. TRUNCATE

Solution

1. Step 1: Understand the function purpose

   ROUND changes a number to the nearest integer or decimal place, unlike CEIL or FLOOR which only round up or down.

2. Step 2: Compare with other functions

   CEIL always rounds up, FLOOR always rounds down, TRUNCATE cuts decimals without rounding.

3. Final Answer:

   ROUND -> Option B

4. Quick Check:

   ROUND = nearest rounding [OK]

Hint: ROUND = nearest number, CEIL up, FLOOR down [OK]

Common Mistakes:

• Confusing CEIL with ROUND
• Thinking FLOOR rounds to nearest
• Assuming TRUNCATE rounds

2. Which of the following is the correct syntax to round the number 3.14159 to 2 decimal places in MySQL?

easy

A. ROUND(3.14159, 2)

B. CEIL(3.14159, 2)

C. FLOOR(3.14159, 2)

D. ROUND(3.14159. 2)

Solution

1. Step 1: Check function usage

   ROUND accepts two arguments: the number and the decimal places to round to.

2. Step 2: Identify correct syntax

   ROUND(3.14159, 2) is correct; CEIL and FLOOR do not take decimal places, and ROUND(3.14159. 2) has a syntax error with a dot instead of a comma.

3. Final Answer:

   ROUND(3.14159, 2) -> Option A

4. Quick Check:

   ROUND(number, decimals) syntax [OK]

Hint: ROUND(number, decimals) uses comma, CEIL/FLOOR no decimals [OK]

Common Mistakes:

• Using CEIL or FLOOR with decimal places
• Using dot instead of comma between arguments
• Missing second argument for ROUND

3. What is the result of the query: SELECT CEIL(4.2), FLOOR(4.8), ROUND(4.5);?

medium

A. 5, 4, 5

B. 4, 4, 4

C. 5, 5, 5

D. 4, 5, 4

Solution

1. Step 1: Evaluate CEIL(4.2)

   CEIL rounds up to the next whole number, so CEIL(4.2) = 5.

2. Step 2: Evaluate FLOOR(4.8) and ROUND(4.5)

   FLOOR rounds down, so FLOOR(4.8) = 4. ROUND rounds to nearest integer, 4.5 rounds up to 5.

3. Final Answer:

   5, 4, 5 -> Option A

4. Quick Check:

   CEIL=5, FLOOR=4, ROUND=5 [OK]

Hint: CEIL up, FLOOR down, ROUND nearest (0.5 rounds up) [OK]

Common Mistakes:

• Thinking FLOOR(4.8) is 5
• Rounding 4.5 down instead of up
• Confusing CEIL and FLOOR

4. Identify the error in this query: SELECT CEIL(5.7, 1), FLOOR(3.2), ROUND(2.718);

medium

A. ROUND requires two arguments

B. FLOOR requires two arguments

C. CEIL does not accept two arguments

D. No error, query is correct

Solution

1. Step 1: Check CEIL function arguments

   CEIL only accepts one argument (the number). Passing two arguments causes an error.

2. Step 2: Verify FLOOR and ROUND usage

   FLOOR accepts one argument, ROUND can accept one or two arguments. Both FLOOR(3.2) and ROUND(2.718) are valid.

3. Final Answer:

   CEIL does not accept two arguments -> Option C

4. Quick Check:

   CEIL = 1 argument only [OK]

Hint: CEIL/FLOOR take 1 argument; ROUND can take 1 or 2 [OK]

Common Mistakes:

• Passing two arguments to CEIL or FLOOR
• Assuming ROUND always needs two arguments
• Thinking query has no errors

5. You have a table prices with a column cost containing decimal values. You want to create a new column rounded_cost that rounds cost to the nearest integer but always rounds up if the decimal part is exactly 0.5. Which MySQL expression achieves this?

hard

A. ROUND(cost)

B. IF(cost - FLOOR(cost) = 0.5, FLOOR(cost), ROUND(cost))

C. CEIL(cost - 0.5)

D. CEIL(cost)

Solution

1. Step 1: Understand rounding rules

   In MySQL, ROUND rounds to nearest integer; halfway cases (.5) round away from zero (up for positive numbers).

2. Step 2: Select the correct expression

   CEIL(cost) always rounds up, so it rounds up when decimal part is exactly 0.5, fulfilling the requirement.

3. Step 3: Analyze other options

   A rounds .5 up normally, but does not always round up if decimal is exactly 0.5 (it rounds to nearest). B rounds down for exactly .5, which is incorrect. D fails on .5 cases as CEIL(cost - 0.5) can round down.

4. Final Answer:

   CEIL(cost) -> Option D

5. Quick Check:

   CEIL(cost) always rounds up [OK]

Hint: CEIL(cost) always rounds up, including .5 cases [OK]

Common Mistakes:

• Assuming ROUND always rounds .5 up as needed
• Using conditional that rounds .5 down
• CEIL(cost - 0.5) fails on .5 cases