Data validation rules in Excel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of data validation in Excel?

Data validation helps control what users can enter in a cell. It prevents mistakes by allowing only specific types or ranges of data.

beginner

Name three common types of data validation rules in Excel.

1. Whole number limits (e.g., between 1 and 100)
2. List of allowed values (dropdown)
3. Date or time restrictions

beginner

How do you create a dropdown list using data validation?

Select the cell, go to Data > Data Validation, choose 'List' under Allow, then enter the items separated by commas or select a range with the list values.

beginner

What happens if a user enters invalid data in a cell with data validation?

Excel shows an error message and prevents the entry unless you allow ignoring the warning or customize the alert.

beginner

Can data validation rules be applied to multiple cells at once?

Yes, you can select multiple cells or a range before setting the data validation rule, so all selected cells follow the same rule.

Which Excel feature lets you restrict cell input to a list of choices?

A Pivot Table

B Data Validation with List

C Conditional Formatting

D Filter

Data Validation with List creates a dropdown so users can only pick from allowed options.

What type of data validation rule would you use to allow only numbers between 10 and 50?

A Date

B Text Length

C Whole Number between 10 and 50

D Custom Formula

Whole Number validation lets you set a minimum and maximum number range.

If you want to allow only dates after January 1, 2023, which validation type do you choose?

A Time

B Decimal

C List

D Date greater than 01/01/2023

Date validation can restrict entries to dates after a specific date.

What happens if a user tries to enter invalid data in a validated cell?

A Excel shows an error message

B Excel accepts the data silently

C Excel deletes the data automatically

D Excel formats the cell red

Excel shows an error message and blocks invalid entries by default.

Can you copy data validation rules from one cell to another?

A Yes, by copying and pasting the cell

B Only for dropdown lists

C Only with VBA macros

D No, you must set rules manually

Copying and pasting a cell copies its data validation rules too.

Explain how to set a data validation rule that allows only whole numbers between 1 and 100.

Think about the steps in the Data Validation dialog.

Describe how data validation helps prevent errors in a spreadsheet.

Consider why controlling input is useful.

Practice

1. What is the main purpose of using Data Validation in Excel?

easy

A. To restrict the type of data users can enter in a cell

B. To format cells with colors and fonts

C. To create charts from data

D. To sort data alphabetically

Solution

1. Step 1: Understand Data Validation purpose

   Data Validation is used to control what data can be entered in cells to avoid errors.

2. Step 2: Compare options with purpose

   Only To restrict the type of data users can enter in a cell describes restricting data entry, which matches Data Validation's purpose.

3. Final Answer:

   To restrict the type of data users can enter in a cell -> Option A

4. Quick Check:

   Data Validation = Restrict data entry [OK]

Hint: Data Validation controls input type, not formatting or sorting [OK]

Common Mistakes:

• Confusing Data Validation with cell formatting
• Thinking it creates charts
• Assuming it sorts data

2. Which of the following is the correct way to set a data validation rule that only allows whole numbers between 1 and 10?

easy

A. Allow: List; Source: 1,2,3,4,5,6,7,8,9,10

B. Allow: Whole number; Data: between; Minimum: 1; Maximum: 10

C. Allow: Decimal; Data: greater than; Minimum: 1; Maximum: 10

D. Allow: Text length; Data: less than; Minimum: 1; Maximum: 10

Solution

1. Step 1: Identify rule for whole numbers 1 to 10

   The rule must allow whole numbers only, between 1 and 10 inclusive.

2. Step 2: Match options to rule

   Allow: Whole number; Data: between; Minimum: 1; Maximum: 10 correctly sets Allow to Whole number and Data to between with min 1 and max 10.

3. Final Answer:

   Allow: Whole number; Data: between; Minimum: 1; Maximum: 10 -> Option B

4. Quick Check:

   Whole number between 1 and 10 = Allow: Whole number; Data: between; Minimum: 1; Maximum: 10 [OK]

Hint: Whole numbers need 'Allow: Whole number' with min and max [OK]

Common Mistakes:

• Choosing Decimal instead of Whole number
• Using List instead of number range
• Confusing Text length with number validation

3. If you apply a data validation rule with the formula =ISNUMBER(A1) on cell A1, what will happen when you enter the text "Hello" in A1?

medium

A. The entry will be rejected with an error message

B. The entry will be accepted without error

C. The cell will automatically convert "Hello" to a number

D. The cell will be cleared automatically

Solution

1. Step 1: Understand the formula =ISNUMBER(A1)

   This formula returns TRUE if A1 contains a number, FALSE otherwise.

2. Step 2: Entering "Hello" in A1

   "Hello" is text, so ISNUMBER returns FALSE, violating the validation rule.

3. Final Answer:

   The entry will be rejected with an error message -> Option A

4. Quick Check:

   ISNUMBER rejects text input = The entry will be rejected with an error message [OK]

Hint: ISNUMBER allows only numbers; text causes rejection [OK]

Common Mistakes:

• Thinking text is accepted by ISNUMBER
• Assuming automatic conversion to number
• Believing the cell clears on invalid input

4. You set a data validation rule with the formula =AND(A1>=1, A1<=5) but users can still enter 10 without error. What is the most likely mistake?

medium

A. The formula was entered as text, not as a formula

B. The cell A1 is formatted as Text, not Number

C. The data validation was applied to the wrong cell

D. The formula uses incorrect logical operators

Solution

1. Step 1: Analyze why validation fails

   If users enter 10 and no error shows, validation is not working on that cell.

2. Step 2: Check common causes

   Most likely, the validation rule was applied to a different cell, not the one users edit.

3. Final Answer:

   The data validation was applied to the wrong cell -> Option C

4. Quick Check:

   Wrong cell validation = The data validation was applied to the wrong cell [OK]

Hint: Always confirm validation applies to correct cells [OK]

Common Mistakes:

• Entering formula as text disables validation
• Ignoring cell format effects
• Assuming formula logic is wrong without checking range

5. You want to create a data validation rule that allows only dates in the current year. Which custom formula should you use?

hard

A. =AND(ISNUMBER(A1), YEAR(A1)=TODAY())

B. =AND(ISDATE(A1), YEAR(A1)=YEAR(TODAY()))

C. =AND(ISNUMBER(A1), MONTH(A1)=YEAR(TODAY()))

D. =AND(ISNUMBER(A1), YEAR(A1)=YEAR(TODAY()))

Solution

1. Step 1: Understand the goal

   Allow only dates in the current year, so check if A1 is a number (dates are numbers) and year matches current year.

2. Step 2: Evaluate options

   =AND(ISNUMBER(A1), YEAR(A1)=YEAR(TODAY())) uses ISNUMBER (correct for dates), and YEAR(A1)=YEAR(TODAY()) which matches current year.

3. Final Answer:

   =AND(ISNUMBER(A1), YEAR(A1)=YEAR(TODAY())) -> Option D

4. Quick Check:

   Check date number and year match = =AND(ISNUMBER(A1), YEAR(A1)=YEAR(TODAY())) [OK]

Hint: Use ISNUMBER and YEAR to validate dates in current year [OK]

Common Mistakes:

• Using ISDATE which is not an Excel function
• Comparing MONTH to YEAR
• Comparing YEAR to full date instead of year only