what is binary and why do we use it?
DESCRIPTION
Introduction to binary numbers and simple calculator using Excel.TRANSCRIPT
What is binary?
Why do computers use it?
The first computer was NOT a binary machine
.. but that was a mistake
Which is clearer?
Which is clearer?
Confident?
recursive
89635839
010011010
How binary works
To convert to decimal, just add them up!0*128 + 1*64 + 0*32 + 1*16 + 1*8 + 1*4 + 1*2 + 0*1
0
Units (1s)
1
2s
1
4s
1
8s
1
16s
0
32s
1
64s
0
128s
Just two numbers, 0 and 1 Place matters
Can you do it?
Decimal number 128 64 32 16 8 4 2 1
0 0 0 0 0 1 1 0
0 1 0 0 0 1 1 1
0 0 0 0 0 0 0 0
0 1 0 1 0 1 0 1
1 0 1 1 1 1 0 1
0 0 1 0 1 0 1 1
1 1 1 1 1 1 1 1
Can you do it the other way?
Decimal number 128 64 32 16 8 4 2 1
6
7
15
23
62
127
96
What’s the bottom of Excel?
Excel binary to decimal
Use eight cells for the binary number
Put the magic numbers below: 128,64,32,16,8,4,2,1 Multiply * Add the results =sum() Make it look good
Can you do it the other way round?
Excel decimal to binary
Use =div() to divide by two Keep doing it Use =mod() to find the remainder That gives you the binary digits
Decimal number here=int(/2)
=mod(,2)
Can you ….
Write out a binary number? Convert binary to decimal? Convert decimal to binary? Use multiply in a spreadsheet? Drag-Copy in a spreadsheet? Use =SUM() in a spreadsheet? Use =INT() in a spreadsheet? Use =MOD() in a spreadsheet?