← ACARA Digital Technologies Years 7–8

The BIN2DEC spreadsheet function

BIN2DEC changes a binary number into its decimal value. =BIN2DEC(1101) gives 13. Use it to check a hand conversion.

Part of: ACARA Digital Technologies Years 7–8 — Binary Number Representation — Module 25

Understanding The BIN2DEC spreadsheet function in ACARA Digital Technologies Years 7–8

What it does: BIN2DEC gives 22 for 10110 (16 + 4 + 2), so the check shows TRUE. If it showed FALSE, the hand conversion has a mistake. The quotes keep the leading zeros as typed text. BIN2DEC still reads the value as binary 101, which is 5. BIN2DEC means binary to decimal. The function that goes the other way is DEC2BIN. The 1101 is read as binary: 8 + 4 + 0 + 1 = 13. BIN2DEC does not treat it as one thousand one hundred and one. BIN2DEC is a good way to check your work. A mismatch means you should look for a slip in your place values or adding.

Common mistakes: Spreadsheets compare values with a single = sign, not ==. The check should be =IF(B1=C1,"OK","Check"). Binary numbers only contain the digits 0 and 1, so 1121 gives an error. It should be =BIN2DEC(1101), which gives 13.

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

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Learning
Duo
What does the spreadsheet function BIN2DEC do?
Changes a binary number into a decimal numberChanges a decimal number into a binary number
Matches
=BIN2DEC(1102)
↓
The number 1102 contains a 2, and binary only uses the digits 0 and 1, so the spreadsheet shows an error (#NUM!).
Applying
Meanings
Term
=BIN2DEC(1101)
Meaning
BIN2DEC changes a binary number into its decimal value. =BIN2DEC(1101) gives 13. Use it to check a hand conversion.
Practice
=BIN2DEC("00001101")
Testing
Gaps
=(1101)
Check Answer
Spots
3C1: 13
4D1: =IF(B1==C1,"OK","Check")

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Quick Questions

1. What does the spreadsheet function BIN2DEC do?
A. Changes a decimal number into a binary number
B. Changes a binary number into a decimal number ✓
BIN2DEC means binary to decimal. The function that goes the other way is DEC2BIN.
2. What value does =BIN2DEC(1101) give?
A. 13 ✓
B. 1101
The 1101 is read as binary: 8 + 4 + 0 + 1 = 13. BIN2DEC does not treat it as one thousand one hundred and one.
3. Which formula changes the binary number 111 into decimal?
A. =DEC2BIN(111)
B. =BIN2DEC(111) ✓
BIN2DEC reads the number as binary. =BIN2DEC(111) gives 7.
4. You converted 1010 to decimal by hand. Which formula checks your answer?
A. =BIN2DEC(1010) ✓
B. =DEC2BIN(1010)
=BIN2DEC(1010) gives 10. If your hand answer matches, your conversion is probably right.
5. =BIN2DEC(11001) shows 25, but your hand conversion gave 23. What should you do?
A. Recheck your working, because the spreadsheet disagrees ✓
B. Keep 23, because hand answers are always right
BIN2DEC is a good way to check your work. A mismatch means you should look for a slip in your place values or adding.

Match the Pairs

=BIN2DEC(1101) → Changes the binary number 1101 into decimal and shows 13
=BIN2DEC(111) → Changes the binary number 111 into decimal and shows 7
Check a hand conversion: you worked out that 10110 is 22, so ask the spreadsheet if it agrees → =BIN2DEC(10110)=22
Type binary with leading zeros as text by putting it in quotes, and still get its decimal value → =BIN2DEC("00000101")
=BIN2DEC(1102) → The number 1102 contains a 2, and binary only uses the digits 0 and 1, so the spreadsheet shows an error (#NUM!).
=DEC2BIN(1101) → DEC2BIN goes the wrong way. It treats 1101 as a decimal number and turns it into binary, instead of turning binary 1101 into decimal.

Key Term

=BIN2DEC(1101)
BIN2DEC changes a binary number into its decimal value. =BIN2DEC(1101) gives 13. Use it to check a hand conversion.

Fill in the Blanks

1. =BIN2DEC(1101)
Hint: Type the spreadsheet function name that changes a binary number into decimal.
2. =BIN2DEC(1101)
Hint: Type the symbol every spreadsheet formula must start with.
3. =BIN2DEC(1101)=13
Hint: Type the operator that checks whether the result equals 13. It gives TRUE when your hand conversion is right.
4. =BIN2DEC("00001101")
Hint: Type the function name that reads binary typed as text with leading zeros.
5. =IF(BIN2DEC(1010)=10,"OK","Wrong")
Hint: Type the decimal value that your hand conversion of 1010 should give.

Spot the Error

Question 1
A A1: 1101
B B1: =BIN2DEC(A1)
C C1: 13
D D1: =IF(B1==C1,"OK","Check")
Line D — Spreadsheets compare values with a single = sign, not ==. The check should be =IF(B1=C1,"OK","Check").
Question 2
A =BIN2DEC(1121)
B Result: 13
C Check: 8+4+0+1 = 13
Line A — Binary numbers only contain the digits 0 and 1, so 1121 gives an error. It should be =BIN2DEC(1101), which gives 13.
Question 3
A A2: '00001010
B B2: =BIN2DEC(A2)
C Result in B2: 1010
Line C — BIN2DEC gives the decimal value and the leading zeros do not change it. 00001010 in binary is 8+2 = 10, so B2 shows 10.
Question 4
A A1: 111
B B1: =DEC2BIN(A1)
C Result: 7
Line B — DEC2BIN goes the other way, from decimal to binary. To convert binary 111 into decimal 7 you need =BIN2DEC(A1).
Question 5
A BIN2DEC("10000")
B Hand: 16+0+0+0+0 = 16
C Result: 16
Line A — A spreadsheet formula must start with an equals sign. Without it the cell just shows text. It should be =BIN2DEC("10000").

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