How the hell is this not 32?

Diddums · 22 Mar 2018 at 15:47

In what world is this not 32? Come on :confused:

MrRoper · 22 Mar 2018 at 15:49

http://www.ultimatemaths.com/order-of-operation-bidmas.htm

Luke · 22 Mar 2018 at 15:50

-7.12

bloodiedathame · 22 Mar 2018 at 15:50

3-20 = -17

53 / -17 = x

x - 4 = the right answer

Luke · 22 Mar 2018 at 15:51

bloodiedathame said:
3-20 = 17

No, 3-20 is minus 17

Diddums · 22 Mar 2018 at 15:52

Luke said:
-7.12

This is the correct answer. I need a break from this, it's doing my head in. I swear all I can see is mathematical symbols everywhere now.

bloodiedathame · 22 Mar 2018 at 15:52

Luke said:
No, 3-20 is minus 17

Just testing.

Diddums · 22 Mar 2018 at 15:53

bloodiedathame said:
Just testing.

Mhmmmmm

Dis86 · 22 Mar 2018 at 15:53

Luke said:
-7.12

That's what I get.

Luke · 22 Mar 2018 at 15:54

So 3-20 is -17. It's in brackets so you perform this first.
Division is next.
53 divided by -17 = -3.117....
Lastly subtract 4 = -7.117...

The question specifies rounding to 2 decimal places. = -7.12

d_brennen · 22 Mar 2018 at 15:56

Resolve the brackets first, innit

danlightbulb · 22 Mar 2018 at 15:57

Diddums said:
This is the correct answer. I need a break from this, it's doing my head in. I swear all I can see is mathematical symbols everywhere now.

We only had one of these a few weeks ago. The issue is caused by the use of the old fashioned divide symbol and assumptions on term grouping. If written as:

[53/(3-17)] -4 then no issue.

I fail to understand how you got 32 as the answer though??

Luke · 22 Mar 2018 at 15:58

I was only taught BODMAS/BIDMAS when I was in my 30's. I never touched on it at school.

Diddums · 22 Mar 2018 at 15:59

Luke said:
So 3-20 is -17. It's in brackets so you perform this first.
Division is next.
53 divided by -17 = -3.117....
Lastly subtract 4 = -7.117...

The question specifies rounding to 2 decimal places. = -7.12

This is exactly what I don't get. 53/-17 comes up as a completely different answer. I should probably not use Windows calculator tbh.

Diddums · 22 Mar 2018 at 16:01

Luke said:
I was only taught BODMAS/BIDMAS when I was in my 30's. I never touched on it at school.

This is probably why I messed it up. For me it's been almost 25 years and I haven't touched it since. I was great at maths back then so went in guns blazing and made a tit of myself.

robfosters · 22 Mar 2018 at 16:01

definitely -7.12. Just checked it out on a scientific calculator that allows me to put the whole sum in as written.

robfosters · 22 Mar 2018 at 16:03

Diddums said:
In what world is this not 32? Come on

That looks like a question from an OU TMA.

danlightbulb · 22 Mar 2018 at 16:03

Diddums said:
This is exactly what I don't get. 53/-17 comes up as a completely different answer. I should probably not use Windows calculator tbh.

blimey mate if you cant get 53/-17 right then there is no hope. dont blindly type things into calculators.

Burnsy2023 · 22 Mar 2018 at 16:03

Diddums said:
This is exactly what I don't get. 53/-17 comes up as a completely different answer. I should probably not use Windows calculator tbh.

I just used the windows calc and it gave the right answer...

glenimp617 · 22 Mar 2018 at 16:04

This is the internet, where any and all maths questions are resolved using BODMAS!