New Math vs. Old Math
Aug 12, 2021 18:07:18 #
Vince68 wrote:
I'm not as old as most here it seems (turned 70 th... (show quote)
Add for parens: Do the innermost parentheses in a set first, working your way out to the outermost parentheses of the set.
Aug 12, 2021 18:09:34 #
Have to laugh. The "New Math" for me was 1+1=10.
That was a Loooong time ago! Like ≈1963.
That was a Loooong time ago! Like ≈1963.
Aug 12, 2021 18:29:14 #
First of all the equation is poorly written. There is an implied multiplication that is not explicitly presented. So I tried to use my calculator.
The first thing I did was to just press the buttons on my iPhone calculator as the equation was written. 8/2 resulted in 4. I then pressed ( but nothing changed. I then pressed 2+2. When I pressed ) I got 4. When I pressed =, I got 2
I then found another calculator, an ancient TI 8A II Plus. Pressing the keys in sequence yielded a result of 2.
Then an old Radio Shack BC-4012 scientific calculator. 8/2( gives 2. Pressing 2 gives 22. Pressing +2) gives 0.36363636. = does not change that "result".
I have lots of other calculators but none of the others have the parentheses.
Clearly the calculators I have do not use PEMDAS. The Radio Shack calculator gives particularly interesting results. It's pretty old so maybe the "(" button is not functional.
The first thing I did was to just press the buttons on my iPhone calculator as the equation was written. 8/2 resulted in 4. I then pressed ( but nothing changed. I then pressed 2+2. When I pressed ) I got 4. When I pressed =, I got 2
I then found another calculator, an ancient TI 8A II Plus. Pressing the keys in sequence yielded a result of 2.
Then an old Radio Shack BC-4012 scientific calculator. 8/2( gives 2. Pressing 2 gives 22. Pressing +2) gives 0.36363636. = does not change that "result".
I have lots of other calculators but none of the others have the parentheses.
Clearly the calculators I have do not use PEMDAS. The Radio Shack calculator gives particularly interesting results. It's pretty old so maybe the "(" button is not functional.
Aug 12, 2021 19:18:25 #
DirtFarmer wrote:
First of all the equation is poorly written. There is an implied multiplication that is not explicitly presented. So I tried to use my calculator.
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My Droid calculator changed "2(" to "2*(" on the fly when I hit the "(" key.
Nothing wrong with implied multiplication.
Years ago, before calculators and computers, it was perfectly acceptable to hand write an equation as 2(A+B).
Aug 12, 2021 20:20:29 #
Aug 13, 2021 00:20:57 #
PEMDAS rules applied:
8/2(2+2)= ?
8/2*4 Operation in Parens first
No exponents
4*4=16 Mult & Div in L to R order
PEMDAS rule properly applies only if the expression is taken as being written in a single line, such that "/" = "÷".
Excel doesn't interpret it that way: "=8/2*(2+2)" returns 16.
For PEMDAS to result in 1, the expression would have to be written 8/(2(2+2))= ?
Without some convention to determine the order of operations, 8/2(2+2)= ? would be ambiguous.
8/2(2+2)= ?
8/2*4 Operation in Parens first
No exponents
4*4=16 Mult & Div in L to R order
PEMDAS rule properly applies only if the expression is taken as being written in a single line, such that "/" = "÷".
Excel doesn't interpret it that way: "=8/2*(2+2)" returns 16.
For PEMDAS to result in 1, the expression would have to be written 8/(2(2+2))= ?
Without some convention to determine the order of operations, 8/2(2+2)= ? would be ambiguous.
Aug 13, 2021 05:52:26 #
Aug 13, 2021 06:36:21 #
Aug 13, 2021 07:18:23 #
whfowle
Loc: Tampa first, now Albuquerque
When I studied math back in the day, the answer would be 1. I was taught that you simplified what was in parenthesis first so 2+2 is 4. Then you further simplify the denominator so 2 x 4 is 8. Then you solve the equation of 8 divided by 8 and get 1. I have no idea how you can get 16 from this expression.
Aug 13, 2021 07:40:07 #
whfowle wrote:
When I studied math back in the day, the answer would be 1. I was taught that you simplified what was in parenthesis first so 2+2 is 4. Then you further simplify the denominator so 2 x 4 is 8. Then you solve the equation of 8 divided by 8 and get 1. I have no idea how you can get 16 from this expression.
You made the assumption that the denominator is everything.
If the formula was written properly, it is not.
(See my comment above.)
Aug 13, 2021 08:04:44 #
Well, I am glad you all enjoyed the math exercise.... You think the dialogue on here was tough, you should have seen the thread on FB.... I pity a generation of folks who can't think math at all but just rely on pushing pictured buttons on retail ring up machines.... I enjoyed the reasoning processes of all those that contributed. I guess if our individual methods got us this far no need to change now ! Have a great, safe day... Bob
Aug 13, 2021 08:07:12 #
Aug 13, 2021 08:13:45 #
Aug 13, 2021 08:22:19 #
MrBob wrote:
We seem to have a lot of Old Timers around these parts so I would expect PEMDAS to prevail... Very simple equation that everyone seems to disagree on.... I know the REAL answer but I am not a spoiler. Can we get it in 1 page ?
8/2(2+2)= ?
8/2(2+2)= ?
16
Aug 13, 2021 08:23:42 #
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