Date post: | 22-Nov-2014 |
Category: |
Education |
Upload: | grahamwell |
View: | 69 times |
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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?