Solve this equation
- Thread starter ISUCyclones2015
- Start date
Actually PEMDAS is parentheses. Exponents, multiplication and division, addition and subtraction.
Answer is 16.
and I'm 56.
I'm 52 (MIS) and my wife (Trans log) is 49. We both said the answer was 1. Then we asked our son (MSE 1st year) who just finished Calc II and he said 16 and was very confident.
We all agree the problem was written incorrectly. For us older people that use PEMDAS but not the left to right rule the answer was 1. But using the l to r method it is 16.
He sold me when he put this in our phone calculator and it showed 16. As you can see from the old Casios it was not clear in the past.
Left to right using PEMDAS would be (2+2)=4, then 8÷2=4, then 4*4=16.
We all agree the problem was written incorrectly. For us older people that use PEMDAS but not the left to right rule the answer was 1. But using the l to r method it is 16.
He sold me when he put this in our phone calculator and it showed 16. As you can see from the old Casios it was not clear in the past.
Left to right using PEMDAS would be (2+2)=4, then 8÷2=4, then 4*4=16.
That is how I understand PEMDAS.
KidSilverhair
Well-Known Member
This is all that needs to be said. These poorly written problems, seemingly simple at first glance but intentionally formatted in a way to give multiple “correct” answers, are posted on the internet only to get us talking about it and all riled up.
Any kind of mathematical problem that actually required a solution would never be formatted in this way. It’s all for internet clicks and outrage and talking past each other.
Show your work and you get 100% if you answered 16 or 1. The 3 votes for other work at Wal-Mart. Kidding...
HP's used reverse polish notation, I never saw a TI that did, maybe they were out there. Still use my HP-42S today. My favorite math class title at ISU was "Partial differential equations and complex variables with application."BTW - modern calculators don't use the "Reverse Polish Notation" of the older TI scientific calculators, which may contribute to confusion with PEMDAS rules. Dunno. Math was a while back. Loved it...until I got to trig. I'm too much of a straightline thinker to handle theoretical math. If you can't solve an equation, you don't invent an imaginary number to fix it.
Apparently this PEMDAS thing is something someone came up with for people who can't just remember simple rules. Seems common coreish. Never heard of it.
You do not carry out each operation before starting the next. Multiplication and division are carried out in one step left to right. Finally, you carry out addition and subtraction left to right. It is all just silly convention, but is important there is a standard, and there is no such thing as an implied parenthesis. I'm sure somewhere on the internet someone will say differently.
Correct. The problem with the acronym is that people think you do multiplication before division which is not true. As you note, they take the same precedent so you do them left to right.
I agree PEMDAS is a mnemonic used to help remember the rules for simplifying mathematical expressions, and it is just a convention used in mathematics education. On https://plainmath.net/algebra-i/34178-fill-in-the-blank-with-a-number-to-make-the-expression-a-perfect-square-x I found the help I needed. I have difficulties with equations and algebra, so exercises like filling the blank with a number to make the expression a perfect square give me a great headache. Fortunately, the math service helps and the rules for carrying out the operations are to perform any calculations inside parentheses, exponents, multiplication and division from left to right, and addition and subtraction from left to right. However, there is a standard in mathematics so that everyone follows the same rules and obtains the same results when simplifying expressions.
Last edited:
Yes. they are different expressions.
Your expression is (2 * (2+2)) / 8 = (2 * 4 ) / 8 = 8 / 8 = 1
The original expression is (8 / 2) * (2 + 2) = 4 * 4 = 16