Poor numeracy 'blights the economy and ruins lives'

kabayiri

I have a confession related to Maths.

Some time back there was a thread in this forum about an 11+ question. It involved a circle of specified diameter rotating its way around the outer perimeter of an equilateral triangle. 'How many rotations?' was the question.

I enjoyed the question, and set it as a challenge to 2 different sets of maths teachers during the open evening tour at secondary school.

I was dismayed that only one of the 4 teachers managed to half guess the answer, the others got it just plain wrong.

My DH explained that I was 'persecuting' said teachers. Hmm, go figure! I shall probably rot in Maths Hell.

davetrousers

davetrousers wrote: »

2 + 3 x 5 = 17

ILW wrote: »

2 + (3 x 5) = 17
Corrected.

Oh dear you fell into my trap.

Multiply and divide before you add and subtract. One of the fundamental rules of maths.

2 + 3 x 5 = 17


PS, please can you un-amend your quote. I don't want an erroneous quote being attributed to me? Thanks

PasturesNew

davetrousers wrote: »

Multiply and divide before you add and subtract. One of the fundamental rules of maths.

2 + 3 x 5 = 17

Interestingly, or not, if you copy/paste 2+3*5 into Google, it actually makes the appropriate correction and gives the correct answer.

davetrousers

PasturesNew wrote: »

Interestingly, or not, if you copy/paste 2+3*5 into Google, it actually makes the appropriate correction and gives the correct answer.

Interesting, but the thing is no correction is actually required. Rules of maths govern that it equals 17.

2 + 3 x 5 = 17
3 x 5 + 2 = 17
(2 + 3) x 5 =25
2 + (3 x 5) = 17 But the brackets are superfluous

chewmylegoff

LydiaJ wrote: »

The problem for a lot of people isn't operating the calculator, it's knowing what to do with the numbers. Almost anyone can use a calculator to multiply three numbers together. The problem is knowing which numbers to add and which to multiply. Suppose I tell you that a room is 2.5m wide, 3.2m long and 2.2m high, and I am buying paint that does 13 square metres per litre when covering a smooth wall, but I need an extra 20% because the previous owner has put annoying textured wallpaper up. With a calculator, you could work out how much paint I need, couldn't you? But a lot of people couldn't, and that's what we're talking about.

no because you haven't told me the dimensions and number of doors and windows in the room.

but for the avoidance of doubt, the answer is "whatever the person i'm paying to do the decorating says"!

nomoreboomandbust

Pennywise wrote: »

I've been saying this for years.

I'm an accountant and far too many times have to spend a lot of time with clients re very basic numeracy issues, such as simple percentages and calculations, etc.

We're not talking about uneducated people here - it's common for knowledge workers such as business consultants, IT contractors, etc to have very poor basic numeracy skills.

i wouldn't complain though, I am sure it keeps many accountants in business

wotsthat

davetrousers wrote: »

Interesting, but the thing is no correction is actually required. Rules of maths govern that it equals 17.

2 + 3 x 5 = 17
3 x 5 + 2 = 17
(2 + 3) x 5 =25
2 + (3 x 5) = 17 But the brackets are superfluous

That's right.

I was taught BODMAS - I can't remember ws the "O" was though.

sparklefrog

Where I work we calculate drug dosages
eg drug is 10mg in 1 ml and we need to give 4mgs. so 0.4mls
but there is a formula to work it out which is 'what you want' divided by 'what you have' times 'volume its in'. so it would be 4/10 x 1
to this day it still amazes me that people get out calculators for the above calculation and not only that but they use the full formula and times everything by 1 (the volume)
I want to slap the calculator out of their hands.

chewmylegoff

sparklefrog wrote: »

Where I work we calculate drug dosages
eg drug is 10mg in 1 ml and we need to give 4mgs. so 0.4mls
but there is a formula to work it out which is 'what you want' divided by 'what you have' times 'volume its in'. so it would be 4/10 x 1
to this day it still amazes me that people get out calculators for the above calculation and not only that but they use the full formula and times everything by 1 (the volume)
I want to slap the calculator out of their hands.

to be honest, if i was calculating a drug dosage that i was giving to someone else, i would check it on a calculator and probably an abacus as well, no matter how straightforward the calculation was.

ILW

sparklefrog wrote: »

Where I work we calculate drug dosages
eg drug is 10mg in 1 ml and we need to give 4mgs. so 0.4mls
but there is a formula to work it out which is 'what you want' divided by 'what you have' times 'volume its in'. so it would be 4/10 x 1
to this day it still amazes me that people get out calculators for the above calculation and not only that but they use the full formula and times everything by 1 (the volume)
I want to slap the calculator out of their hands.

The problem with just using a calculator for that sort of job, is that if you do not have a basic grasp of the maths, it is easy to put a decimal in the wrong place and not notice the error. Which could be fatal.