# Talk

## Maths experts how would you work this out using BODMAS?

(21 Posts)
LilyTucker Sun 06-Sep-15 10:52:23

20-10./.2+14

./. is my attempt at the division sign

Also could you talk me through it.

DoreenLethal Sun 06-Sep-15 10:56:27

Brackets - none
Of - none
Division - 10 divided by 2 = 5
So 20-5+14 = 39.

araminem Sun 06-Sep-15 10:57:12

First dó 10/2=5. This leaves you with 20-5+14=29.

You first do the division bit than the addition/subtraction.

BeautifulBatman Sun 06-Sep-15 10:59:36

20 -(10÷2)=15.
15+14=29.

MarietteL Sun 06-Sep-15 10:59:42

29

LilyTucker Sun 06-Sep-15 11:01:50

It's either 19,29,14,15 or 24

19 is wrong

LilyTucker Sun 06-Sep-15 11:03:26

Dp says that is wrong because it's addition before subtraction.

LilyTucker Sun 06-Sep-15 11:04:26

Also how do you choose where to put the brackets in?

PosterEh Sun 06-Sep-15 11:04:41

29

BeautifulBatman Sun 06-Sep-15 11:04:56

DP says what is wrong? I'm no 'expert', but I do teach maths. 29 is the right answer.

PosterEh Sun 06-Sep-15 11:07:04

You put the brakets around the bit you do first. So using bodmas the division is first in that equation so you can put brackets round the division of it makes it easier to see what is going on (you don't need the brackets because bodmas tells you what to do first but it can make it easier to see).

capricalia Sun 06-Sep-15 11:07:08

Brackets would be before the 10 and after the 2 as far as I remember

Additional and subtraction usually done at the same time - it's been a while.

Huntthepigsear Sun 06-Sep-15 11:07:11

Addition and subtraction are both third order sums, so should be done left to right.
29 is correct.

LilyTucker Sun 06-Sep-15 11:09:06

Cool,got to fly will go over it later.

Many thanks,that's a great help all.

SevenSeconds Sun 06-Sep-15 11:09:18

You don't choose where to put the brackets - there are no brackets in this sum. If there were you'd do them first.

DoreenLethal Sun 06-Sep-15 11:13:05

Sorry - slip of the finger 29!

Not 39

BeautifulBatman Sun 06-Sep-15 11:13:28

Sorry - I put the brackets in to demonstrate the operation that had to be done first before the rest of the operations were completed.

Sun 06-Sep-15 11:13:44

10/2 first and then the rest doesnt matter because its just adding and subtracting. So the answer is 29.

The O stands for order, but it doesnt mean order of which way round you do things, its the same as Indices (so squares and cubes)

Sun 06-Sep-15 11:16:17

Remember that all adding and subtracting is, is moving up and down a number line, adding you are moving up, subtracting you are moving down. That is why it doesnt matter which one you do first out of the two. To see it, write yourself out a number line from -30 through 0 to +30 and have a play

It doesnt matter if you add or subtract first.
Division first ( unless the line goes all the way over the 2+14). So get
20-5+14.

Then it doesn't matter if you do 20+14, and take the 5 away, or if you take 5 from the 20, then add the 14, you still get 29.

Unless DH is putting brackets to make it read 20-(5+14), which is completely changing the mathematical sentance to 20-5-14.

Tue 08-Sep-15 19:31:45

You do multiplication/division first and then work your way from left to right doing the addition and subtraction.

Join the discussion

Registering is free, easy, and means you can join in the discussion, get discounts, win prizes and lots more.

Register now