Bits, bytes and binary

Binary

  • Binary is a system that uses 0s and 1s that can represent data
  • Computers use binary because electricity has two states: on and off
  • These 1s and 0s are called bits

Bit

  • A bit is the smallest unit of data a computer can use
  • A bit is either 0 or 1
  • A bit can be used to store
    • A colour (black/white)
    • A switch (on/off)
    • An answer (yes/no)

Byte

  • 1 byte is 8 bits of data
  • A byte can be used to store
    • A number (0-255)
    • A letter

Converting binary

Convert the binary number 00000011 to denary

  1. Each column in binary has a value: 128, 64, 32, 16, 8, 4, 2, 1
  2. Write the binary number into the table
  3. Add the columns that have a 1
128 64 32 16 8 4 2 1 Answer
0 0 0 0 0 0 1 1 = 2 + 1 = 3

Convert the number 7 to binary

  1. Write the place values across: 128, 64, 32, 16, 8, 4, 2, 1
  2. Starting at the left put a 1 in a columns needed to create 7
  3. Put 0 in all other columns
128 64 32 16 8 4 2 1
0 0 0 0 0 1 1 1 = 7

Targets

I can state the definition of a bit

I can state the definition of a byte

I can explain why computers use binary to store data

I can convert binary to denary

I can convert denary to binary