Number system
IGCSE Computer Science (0478)
Data Representation
Introduction
Why computers use binary (how binary represents data)
Number system
Introduction
Number Conversions
Addition of Binary Numbers
Logical binary shifts (positive 8-bit integers)
Two’s Complement (Signed: Positive and Negative Numbers)
Use of the Hexadecimal System
Text, Sound and Image
Text, Sound and Images
File Types
Data storage and File compression
Measurement of the Size of Computer Memories
Lossless and Lossy File Compression
Number system
Logical binary shifts (positive 8-bit integers)
Logical Binary Shifts (Positive 8-bit Integers)
#
Logical Left Shift (
<< 1
)
#
What happens?
Bits move one position to the
left
.
A
0
is added on the
right
end.
Effect:
Multiplies the number by 2 (if no overflow occurs).
Example:
0011 0101
(53 in decimal)
Left shift by 1 →
0110 1010
(106 in decimal)
Logical Right Shift (
>> 1
)
#
What happens?
Bits move one position to the
right
.
A
0
is added on the
left
end.
Effect:
Divides the number by 2 (integer division, fractional parts dropped).
Example:
0011 0101
(53 in decimal)
Right shift by 1 →
0001 1010
(26 in decimal)
Practice Answers — Logical Binary Shifts
#
1.
Shift 0001 1010 left by 2
Step 1:
Shift left by 1
0001 1010 → 0011 0100
Step 2:
Shift left by 1 again
0011 0100 → 0110 1000
Final result:
0110 1000
Decimal value:
104 (since 64 + 32 + 8 = 104)
2.
Shift 1000 0001 right by 1
Step 1:
Shift right by 1
1000 0001 → 0100 0000
Final result:
0100 0000
Decimal value:
64
Modified at
2025-08-11 07:32:29
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Addition of Binary Numbers
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Two’s Complement (Signed: Positive and Negative Numbers)