Mathematics question.
- Thread starter 86JR
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Think of it this way
(A + B) * (A + B) = A^2 + 2AB + B^2
Therefore
32 * 32 =(30 + 2) *(30 + 2)= 30^2 + 2( 30*2) + 2^2 = 900 + 120 + 4 = 1024
Simples!
You missed out the 2AB!
(There are no Dumb questions, Only Dumb answers!)
How do you do all that in your head?
Soldato
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Easy tiger 0x is notation that we're using base 16. You don't want to be taxing your head so early in the day
Soldato
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Hex is a base 16 system, so 20 = 32...
1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1a, 1b, 1c, 1d, 1e, 1f, 20... and so on.
Takes a while to get your head around as we're so hard-wired to work in base10.
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I am mid 50's! No calculators back then!
Back in the day we would work out square roots to 4 decimal places in our heads..
For Fun!
Soldato
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I am mid 50's! No calculators back then!
Back in the day we would work out square roots to 4 decimal places in our heads..
For Fun!
Bet you got caught cheating by using a slide rule
A bit before my time, I've seen/handled one but never used one - they look really cool. Must put that on my to do list
I kind of see where you are coming from, but the math does not work like that.
For example in simple person talks.
32*32 is basically 32 32s.
So 32... 32 times...
By splitting it up into two sums, 30*30 is having 30 lots of 30, and 2*2 is having 2 lots of 2... So it will be less than adding both sums together.
Okay I suck at explaining, but this makes sense in my head.
For example in simple person talks.
32*32 is basically 32 32s.
So 32... 32 times...
By splitting it up into two sums, 30*30 is having 30 lots of 30, and 2*2 is having 2 lots of 2... So it will be less than adding both sums together.
Okay I suck at explaining, but this makes sense in my head.
Think of it this way
(A + B) * (A + B) = A^2 + 2AB + B^2
Therefore
32 * 32 =(30 + 2) *(30 + 2)= 30^2 + 2( 30*2) + 2^2 = 900 + 120 + 4 = 1024
Simples!
You missed out the 2AB!
(There are no Dumb questions, Only Dumb answers!)
Similar approach to what I use:
A 2 digit number can be expressed as 10x+y where x and y are the 2 digits.
To square that number:
(10x+y)(10x+y)=100x^2+20xy+y^2
Or in simple "do it in your head" terms:
Take the first digit (x), square it (x^2). put 2 zeroes on the end (100x^2). File that number away
Take the 2 digits and multiply them together (xy), double it (2xy) and put a zero on the end (20xy), file that number away.
Take the second digit (y) and square it (y^2)
Recall the two numbers from earlier and add all 3 parts together.
This is purely Maths, not IT (bits/bytes).
What is 32*32?
The way I do this in my head is 30*30 = 900, and 2*2 = 4. Therefore answer is 904.
However the answer is actually 1024.
This confuses me entirely. I thought I was good at Mathematics.
And here was me thinking that was Arithmetic !
This is purely Maths, not IT (bits/bytes).
What is 32*32?
The way I do this in my head is 30*30 = 900, and 2*2 = 4. Therefore answer is 904.
However the answer is actually 1024.
This confuses me entirely. I thought I was good at Mathematics.
You are stupid, sorry to inform you. To use a simpler example;
11x11 = 121.
10x10 = 100, 1x1 = 1.
101 does not equal 121.
Bet you got caught cheating by using a slide rule
A bit before my time, I've seen/handled one but never used one - they look really cool. Must put that on my to do list
Slide-rules were a brilliant tool, especially for Engineering!
They were not "Precise" enough to yield nonsense 8dp answers and by their nature you had to have an estimate of the answer you were looking for before you even picked one up so magnitude errors were much less likely than with electronic calculators.
Don't forget. some of the most impressive technical achievements of all time were achieved by really smart people without computers using mostly pencils and slide rules! Take away the shiny electronic tools and I doubt if these could be replicated today!
(Electronic computers were coming in during the 50's but they were pretty basic by modern standards. Analogue computers have of course been used for millennia for specific tasks)
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This confuses me entirely. I thought I was good at Mathematics.
Request name change to twoshortplanks
Soldato
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I kind of see where you are coming from, but the math does not work like that.
For example in simple person talks.
32*32 is basically 32 32s.
So 32... 32 times...
By splitting it up into two sums, 30*30 is having 30 lots of 30, and 2*2 is having 2 lots of 2... So it will be less than adding both sums together.
Okay I suck at explaining, but this makes sense in my head.
That's a far more logical explanation to me than the others here
Caporegime
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OP will get plenty of work doing tax returns for politicians imo.
LOL.. Harsh.. But should that not be Oneandahalfshortplanks using OP maths? (I like him he's made me smile
)