Year 11 Units revision 2

• Computing
• Lower Secondary (Key Stage 3)

Y11 revision unit 2 

Make the number 20 in binary.

Learning Objectives

Strengthening: Revise the use of Hexadecimal 

Excelling: Interpret the hexadecimal number line

What is Denary?

Denary, or decimal, is called a base-10 number system. 

• It uses the digits 0-9. It's the most common system for everyday counting and arithmetic

• We use 0-9 to make every other number that exists.
• 127
• 1024

What is Binary?

Binary is a base-2 number system. It uses only two digits: 

• We use 1 and 0 in binary.

• 1 means on and 0 means off.

• These are the only 2 numbers we are allowed to use. 

What is hexadecimal?

Hexadecimal (or hex) is a number system which uses base 16

• Binary Numbers can be long, and at times we need more efficient ways of storing the numbers. 

• 100111101011 in binary is 9EB in hexadecimal.
  

 

Which of these is an example of a denary number?

1. ABC
2. 101010101
3. 01010101
4. 127

Which of these is an example of a Hexadecimal number?

1. A4
2. 1010120102
3. 2Y
4. 127

What digits to Hexadecimal to numbers use

1. 1 and 2
2. 0 to 9
3. 10 to 20
4. 0 - F

Hexadecimal Number Line

• Here is the full Hexadecimal number line. 

What is B in HEX?

1. 12
2. 11
3. 10
4. 15

What is F in HEX?

1. 12
2. 11
3. 10
4. 15

What is D in HEX?

1. 12
2. 13
3. 10
4. 15

What is 8 in HEX?

1. 8
2. A
3. F
4. 4

What is 14 in HEX?

1. D
2. B
3. E
4. F

Binary to Hex conversion

Split the binary number in half

Now have two 4 bit binary numbers

Binary to Hex conversion

Add the binary number line above each 4 bit binary number

We now need to add each 4 bit binary number up

Binary to Hex conversion

We then convert out total numbers to their hex values.

• 11 = B
• 3 = 3
• Final answer = B3

Convert this binary number to HEX

00011001

1. 19
2. A5
3. 4B
4. 59

Convert this binary number to HEX

11110001

1. FA
2. F1
3. F2
4. A2

Convert this binary number to HEX

10101110

1. EA
2. AD
3. AE
4. DA

Practice 

Practice 1

Practice 2

Practice 3