Binary Shifts
Computer Science: OCR A Level, topic 4.1.9
Binary Shifts
A binary shift is a technique for performing multiplication or division on a binary number.
Binary shift
- In a binary shift, each digit is moved one column to the left or the right.
- Extra 0 bits are added to the start or end of the binary number to fill any missing spaces.
Left binary shift
- In a left binary shift, each digit is moved one place to the left.
- This has the effect of multiplying the number by two.
- You must take care, when performing a left shift, that there is no overflow error (where we run out of space to store the last digit of the number).
Right binary shift
- In a right binary shift, each digit is moved one place to the right.
- This has the effect of dividing the number by two.
- You must take care when performing a right shift that no data is shifted off the right hand side. This can cause a loss of accuracy.
Test yourself on Binary Shifts
What is the result of two left binary shifts on 00110100?
How can a number be multiplied by eight using binary shifts?