boit
Hi. I'm having an argument with my friends on the social media over a simple equation we saw on TV (educative program for elementary school kids). This is what was displayed
9*9-7+8=41 (what you'll get working straight off a standard calculator).
One camp is accepting the answer as is displayed above. The opposing camp is giving 78 as the alternative answer citing BODMAS.
Which is the correct application of BODMAS (brackets of division, multiplication, addition and subtraction) or whatever approved method?
Robittybob1
QUOTE (boit+Jun 2 2012, 07:40 AM)
Hi. I'm having an argument with my friends on the social media over a simple equation we saw on TV (educative program for elementary school kids). This is what was displayed
9*9-7+8=41 (what you'll get working straight off a standard calculator).
One camp is accepting the answer as is displayed above. The opposing camp is giving 78 as the alternative answer citing BODMAS.
Which is the correct application of BODMAS (brackets of division, multiplication, addition and subtraction) or whatever approved method?

Did you write it correctly for my calculator gave the answer as 82 which was the same as Excel when I pasted the text yo a cell.
=9*9-7+8 result was 82.
boit
My bad. This is how it was displayed
9*9-7+8/2=
Robittybob1
QUOTE (boit+Jun 2 2012, 08:05 AM)
My bad. This is how it was displayed
9*9-7+8/2=

Well Excel handles that as 78 =9*9-7+8/2 result = 78 so the 9*9 and the 8/2 are calculated before the 81 - 7 + 4 =78
So what order does your calculator handle it? Must be =(9*9-7+8)/2 result 41

boit
Exactly. Done of my phone calculator I get 41 (with non stop iteration). That's how I tried to convince my friends [(9*9)-7+8]/2 though your presentation is better (9*9-7+8)/2. Apparently google gives the same answer as your excel handling i.e. 78. The school management board should sit and explain their answer. I too was misled to think the answer was 41.
Robittybob1
QUOTE (boit+Jun 2 2012, 08:45 AM)
Exactly. Done of my phone calculator I get 41 (with non stop iteration). That's how I tried to convince my friends [(9*9)-7+8]/2 though your presentation is better (9*9-7+8)/2. Apparently google gives the same answer as your excel handling i.e. 78. The school management board should sit and explain their answer. I too was misled to think the answer was 41.

Can the problem be written in such a way that non stop iteration and BODMAS gives the same answer?
boit
Maybe if they leave it at . . .+8 and then write divide the final answer by 2. I don't know . . .
Robittybob1
QUOTE (boit+Jun 2 2012, 10:31 AM)
Maybe if they leave it at . . .+8 and then write divide the final answer by 2. I don't know . . .

That is it, that problem will give different answers depending on the order of the maths.
boit
Thanks Robbity. I appreciate you going out of your way to settle this problem. My friends still feel 78 is the only answer no matter what (as long as I don't introduce brackets and all). Strange how a simple sum can turn into such a big debate. I'll review some other sums I helped my niece with. I fear I may have misled her.
flyingbuttressman
This is simple order of operations.

All math equations should be executed in a set order, unless special characters are used to denote otherwise.

The order is:

1. Exponents, using the carat ^
2. Multiplication, Division and Parenthesis *, /, ()
i.e. 2*3+4 = 10 while 2*(3+4) = 14
3. Addition and subtraction +, -

9*9-7+8/2
81-7+4
78
Robittybob1
QUOTE (flyingbuttressman+Jun 2 2012, 07:05 PM)
This is simple order of operations.

All math equations should be executed in a set order, unless special characters are used to denote otherwise.

The order is:

1. Exponents, using the carat ^
2. Multiplication, Division and Parenthesis *, /, ()
i.e. 2*3+4 = 10 while 2*(3+4) = 14
3. Addition and subtraction +, -

9*9-7+8/2
81-7+4
78

Can that be done on a phone calculator? Can you do the individual operations before adding them together?
flyingbuttressman
QUOTE (Robittybob1+Jun 2 2012, 07:49 PM)
Can that be done on a phone calculator? Can you do the individual operations before adding them together?

Some computers are smarter than others.
If your phone calculator acts like those calculators they use in schools, then it's probably not smart enough to handle the correct order of operations.
dbwjkpl
^^
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