When was the last time you used the quadratic formula?

[chomalungma]

Linked to the maths thread but a very specific example.

(-b +/-square root (b squared - (4ac) ) divided by 2a

Or do you just Google it?

Long division is a common one to find difficult. I am a maths teacher and only learnt how to do it during my teacher training . We didn't cover it at primary school, then at secondary school we did little booklets to "self-learn" (does anyone else remember those little SMP maths booklets that you did by yourself then the teacher marked them and set you the next one). When I was tested at the start of year 7 I was put onto a higher stage of booklets than the ones covering long division, so I never encountered it at all at school. I did meet algebraic long division, and learnt it as a process but did not connect it to numerical long division because that was something I'd never done (and obviously never needed to do!).

I had to sheepishly admit to my teaching practice mentor that I didn't know how to do long division when I was due to teach a lesson on it. She taught me in about 5 minutes. But it's something a lot of adults can't do possibly to do with the crap maths teaching that was the fashion in the late 80s/early 90s

I think long division is hard because people weren't taught with an inbetween method, so they didn't really understand what they were doing.

Whereas is you understand 3846 / 3

Take away 1000 x 3 leaves 546
Take away 200 x 3 leaves 246
Take away 80 x 3 leaves 6
Take away 2 x 3 leaves 0

In total you have 'taken away' 1282 lots of 3.
So the answer is 1282 which is the same as you would get from long/short division / bus stop (depending on what you use and call them).

That does reassure me, I always thought it was the way I had been shown I couldn't get to grips with. It always made me feel very thick which is far from the truth in all other ways except for apparently long division.

2012. Was tutoring someone for maths GCSE.

I don't think my brain retains things like this very well though. I got an A in maths A level in 2008 but really had to think about how to set out a long division the other day 🤨.

The issue with long division (if you want to do it the traditional way without chunking is that you have to do division to do division.

84896 divided by 17

So you need to work out how many 17s go into 84, then work out the remainder, bring it down and keep on going.

Or you could just estimate it.
Or use a calculator

cho Personally I would write down my 17x table at the side, which is just addition. 17, 34, 51, 68, 85,
Then you are really only doing subtraction.

I'm not sure either of those methods is helping I maybe recall we had to split the number we were dividing by you'd divide by 10 and also then 7 and do something else to get the answer.

Thankfully we always have phones with calculators these days, if my dp isn't around I do all maths however simple on my calculator.

3 days ago #mathsteacher

raspberry it's not that easy to explain by text.

That particular equation? Not since maths O'level but I have used algebra at work. Property law.

We weren’t allowed to use that equation and had to work out quadratics long hand. I always knew there was an equation but I never knew what it was, so never for me.
I last did quadratics in 1993.

I have never heard of a quadratic equation and I obtained a B grade in maths GCSE in 2002.

Regina you may not remember the words "quadratic equation" but I would be incredibly surprised if you'd never seen one if you managed to get a B in GCSE maths. It's equations like X squared + 3x +2 =0. You may well have solved them by factorising. You may also have forgotten them the minute you left the exam room, lots of people do

Engineer here, I have used it at work a couple of times when I started my career (20 years ago now), but these days I use a computer for everything.

I have used Pythagoras and using sine, cosine and tangent to work out angles.
I think that's the closest I've got.

Not quadratic equations but I use algebra whenever I can.

I love how life is full of mini word problems that you can translate into algebra like when you have several things to put in the oven at different temperatures and for various times but you have only one oven for example.

That probably doesn’t make sense.

1995

Also the last time I quoted Philip Larkin, considered plant breeding or played hockey.

I didn’t cover it in my first GCSE, when I did the intermediate paper, in 1991 but I did when I be sat it in 2006 and did the higher paper.

I’ve never needed to use it since.

Likewise the names of triangles. The characteristics of certain triangles yes, but never what they are called.

often in last few yrs when DC needed help with their homework :)

Before that when I did calculus revision maybe 5 yrs ago (trying to prep my mind to understand colleagues' work)

I used it today, but then I am a maths tutor. If pupils ask me what's the point of it, I tell them it can be used to predict where a ball will land. If they press further, I set them a problem in it.

With long division, one of my pupils demonstrated "chunking" to me: I learned the traditional method of long division, but I had never heard of "chunking"!

Till he retired my OH used this every day teaching engineering Mathematics at uni

I was top set maths, got an A at GCSE in 1994 and did a term of A Level maths and I am slightly embarrassed to say that I can’t remember the difference between a quadratic and a simultaneous equation. Certainly never used either since.

one
quadratic has x squared eg x^2 + 3x + 2 =0

simultaneous is 2 equations at the same time (simultaneously), with 2 unknowns eg x + y = 7, x - y = 1

Of course, you can have simultaneous equations which involve solving a quadratic, such as solving for the coordinates where a line intersects a circle.