← ACARA Digital Technologies Years 7–8

The DEC2BIN spreadsheet function

A spreadsheet function that converts a decimal whole number into binary text. =DEC2BIN(13) gives 1101. Add places to pad with zeros, e.g. =DEC2BIN(5,8) gives 00000101.

Part of: ACARA Digital Technologies Years 7–8 — Binary Number Representation — Module 24

Understanding The DEC2BIN spreadsheet function in ACARA Digital Technologies Years 7–8

What it does: DEC2BIN can take a cell reference instead of a typed number, so it converts whatever number is in A2. Copying the formula down changes A2 to A3, A4 and so on, so each row's number is converted to binary. DEC2BIN turns a decimal number into binary. BIN2DEC does the opposite and turns binary into decimal. 13 = 8 + 4 + 1, so the place values 8, 4 and 1 are on and the 2 is off. That gives 1101. The second number (8) is the places argument. It pads the answer with leading zeros to 8 digits, so 101 becomes 00000101.

Common mistakes: The function is called DEC2BIN, not DEC2BINARY. A spreadsheet gives an error for a name it does not know. It should be =DEC2BIN(A2). A spreadsheet formula must start with =. Without it the cell just shows the text DEC2BIN(13). It should be =DEC2BIN(13).

Class: _____________________  ·  Name: _____________________  ·  Date: _________

Free printable worksheet with full answer key — or add this module to a class and your students practise it interactively.

🖨 Print worksheet + answer key Add The DEC2BIN spreadsheet function to a class →

This module's key terms are also in a printable crossword (Modules 189–203) and word search (Modules 189–236).

Take this worksheet further — free with Cloodit

Each concept is reinforced from every angle — learned, then applied, then tested.

Learning
Duo
Which formula converts the number 13 into binary?
=DEC2BIN(13)=BIN2DEC(13)
Matches
=DEC2BIN(13,2)
↓
The places argument is too small. 13 needs 4 binary digits (1101), so asking for only 2 places gives an error. Use at least 4, like =DEC2BIN(13,4).
Applying
Meanings
Term
=DEC2BIN(13)
Meaning
A spreadsheet function that converts a decimal whole number into binary text. =DEC2BIN(13) gives 1101. Add places to pad with zeros, e.g. =DEC2BIN(5,8) gives 00000101.
Practice
=DEC2BIN(MAX(B2:D2),8)
Testing
Gaps
=(13)
Check Answer
Spots
2B1: Binary
3B2: =DEC2BINARY(A2)

Cloodit turns curriculum-aligned coding content into journeys students work through one biome at a time.

The 'Woolly Mammoth' badge — Tundra Master, one of Cloodit's 106 collectible badges
Students earn collectable badges

Over 100 of them, across seven natural biomes.

Study Buddy
Students build a real study resource

Turns their work into revision material ready for Flash Cards and Exam study.

Diamond Dash — one of Cloodit's live, competitive Sprint games
Students lock in with Sprints

Live, competitive practice for the start of the lesson or a teacher-led lesson finisher.

A Cloodit certificate of achievement, ready to personalise and print
Custom printable certificates

Honour your top performers, or encourage a student who's trying hard — ready to print in seconds.

Add to class →

Quick Questions

1. Which formula converts the number 13 into binary?
A. =BIN2DEC(13)
B. =DEC2BIN(13) ✓
DEC2BIN turns a decimal number into binary. BIN2DEC does the opposite and turns binary into decimal.
2. What does =DEC2BIN(13) show in the cell?
A. 1101 ✓
B. 1011
13 = 8 + 4 + 1, so the place values 8, 4 and 1 are on and the 2 is off. That gives 1101.
3. What does =DEC2BIN(5,8) show in the cell?
A. 00000101 ✓
B. 10100000
The second number (8) is the places argument. It pads the answer with leading zeros to 8 digits, so 101 becomes 00000101.
4. What is the job of the 8 in =DEC2BIN(5,8)?
A. It sets how many binary digits to show ✓
B. It tells the function to add 8 to the number
The optional places argument sets the width of the result. Spare spaces on the left are filled with 0s.
5. Which cell entry correctly converts the decimal number sitting in cell A2?
A. =DEC2BIN(A2:)
B. =DEC2BIN(A2) ✓
Put the cell reference inside the brackets, just like a number. =DEC2BIN(A2) reads the decimal value in A2 and shows it in binary.

Match the Pairs

=DEC2BIN(13) → Converts the decimal number 13 into binary, giving 1101
=DEC2BIN(5,8) → Converts 5 to binary and pads it with zeros to 8 places, giving 00000101
To get the binary form of the number in cell A2, put the cell reference inside the function → =DEC2BIN(A2)
To convert a whole column of numbers, write the formula once and copy it down so the reference moves to A3, A4 and so on → =DEC2BIN(A2)
=DEC2BIN(13,2) → The places argument is too small. 13 needs 4 binary digits (1101), so asking for only 2 places gives an error. Use at least 4, like =DEC2BIN(13,4).
=DEC2BIN(1101) → The person typed the binary answer instead of the decimal number. DEC2BIN needs the decimal input, so it should be =DEC2BIN(13) to get 1101.

Key Term

=DEC2BIN(13)
A spreadsheet function that converts a decimal whole number into binary text. =DEC2BIN(13) gives 1101. Add places to pad with zeros, e.g. =DEC2BIN(5,8) gives 00000101.

Fill in the Blanks

1. =DEC2BIN(13)
Hint: Type the name of the spreadsheet function that converts a decimal number into binary
2. =DEC2BIN(A2)
Hint: Type the cell reference of the first data row in column A, so the formula can be copied down the column
3. =DEC2BIN(5,4)
Hint: Type the places value that pads the result to a nibble, which is the number of bits in half a byte
4. =DEC2BIN(13)
Hint: Type the symbol that every spreadsheet formula must start with
5. =DEC2BIN(A2,8)
Hint: Type the places value that pads the result to a full byte

Spot the Error

Question 1
A A1: Number
B B1: Binary
C B2: =DEC2BINARY(A2)
D B3: =DEC2BIN(A3)
Line C — The function is called DEC2BIN, not DEC2BINARY. A spreadsheet gives an error for a name it does not know. It should be =DEC2BIN(A2).
Question 2
A DEC2BIN(13)
B Result: 1101
C Result is text, not a number
Line A — A spreadsheet formula must start with =. Without it the cell just shows the text DEC2BIN(13). It should be =DEC2BIN(13).
Question 3
A A2: 5
B B2: =DEC2BIN(8,A2)
C Result: 00000101
Line B — The number to convert comes first and the places (width) comes second. The formula should be =DEC2BIN(A2,8) to give 00000101.
Question 4
A A2: 13
B B2: =BIN2DEC(A2)
C Result: 1101
Line B — BIN2DEC goes the other way, from binary to decimal, so it can't convert 13. To turn a decimal number into binary, use =DEC2BIN(A2).
Question 5
A A1: Number
B B1: 8-bit binary
C A2: 6
D B2: =DEC2BIN(A2,8
E Result: 00000110
Line D — The closing bracket is missing, so the formula is incomplete. It should be =DEC2BIN(A2,8).

Student with a class code? Join your class →