I am mathematically illiterate

[IanB]

Here is a resource for you. They are examples of elementary math exams typical of the British school system for students aged 15 or so. Try them out and see how many questions you can answer successfully. That will give you an idea of what you already might know and what you need to learn:

http://www.bbc.co.uk/schools/gcsebitesize/maths/mocks/

[rstofer]

Only you know where you really are with arithmetic.  Khan Academy starts with pre-school and works up through the first couple of semesters of EE school.  Everything is there!

Start where you think you need.  If it suddenly becomes redundant, skip ahead.

Look at the list and pick a spot.  Maybe pre-Algrebra is the place.  It will assume certain arithmetic skills but they will be demonstrated in use.  If you don't quite follow, back up and look at the video for that specific topic.

https://www.khanacademy.org/math

I'm really old...  As a result, teaching methods have changed vastly and the more modern explanations are often an eye opener.  Every once in awhile I get one of the "Oh, that's where that comes from!" episodes while watching a modern presentation.

I also have troubles staying awake for YouTube lectures.  What I should be doing is solving the problem on a scratch pad in front of me rather than just watching the lecturer.  Hint!  Have a scratchpad and pen/pencil immediately at hand!  Even if I just duplicate what the presenter is doing, I will gain from the repetition.

[rstofer]

I have a separate concern:  Studying math, by itself, is boring!  Furthermore, you don't know where to focus because you don't have an application.  When math is taught as part of a college curriculum there is a certain goal in mind.  It might be Physics, it might be EE, it might even be business.  But there is a goal and math is on the path.  Math itself is seldom the goal unless the major is Math.

How to deal with that?  I have no idea!

Community College seems like one approach but it really depends on where a person is starting from.  There is usually a math placement test and how well that works out will depend on how far along a person gets with Khan Academy.

One of the reasons I like CalcWorkshop is that she presents every single step of every solution.  She even emphasizes the basic arithmetic.  No step is omitted.  Unfortunately, she starts with Algebra and if that is a bridge too far, you have to start somewhere else.

You can see a demo of the Limits series without subscribing.  Unfortunately, Limits comes at the beginning of Calc I and that is definitely a long way down the path.  Nevertheless, you can see the style of instruction and this site might become a resource you use later.

https://calcworkshop.com/courses/
https://calcworkshop.com/limits/

[Vtile]

Everything in higher math is in the end just applying the algebra, the weird hieroglyphs are there just to hide this fact. 

[rstofer]

Everything in higher math is in the end just applying the algebra, the weird hieroglyphs are there just to hide this fact. 

That turns out to be true!  Laplace Transforms exist to convert truly ugly differential equations that probably can't be solved into simple algebraic equations that can.  When we struggled through Algebra I and II in high school, how little did we know how important they would be later on.  We had no idea how important 's' would be.

[IanB]

It shouldn't be overlooked how important conceptual understanding is. To be successful it is not sufficient only to know how to mechanically manipulate symbols. There are underlying ideas that help everything to make sense. Much of the mathematical progression through high school is to build up the concepts.

[Mr. Scram]

It shouldn't be overlooked how important conceptual understanding is. To be successful it is not sufficient only to know how to mechanically manipulate symbols. There are underlying ideas that help everything to make sense. Much of the mathematical progression through high school is to build up the concepts.

I actually feel the opposite. High school has taught me how to manipulate numbers, but when I revisit things now I learn a lot more about the why and how certain tricks and short-cuts actually work.

[rstofer]

Much of the mathematical progression through high school is to build up the concepts.

Which goes back to my point about application.  Learning math for math's sake is a boring proposition.  Taking Physics to emphasize the USE of mathematics is the real learning of math.  At least to me...

[tggzzz]

Everything in higher math is in the end just applying the algebra, the weird hieroglyphs are there just to hide this fact. 

... Or to allow + - * and (if you are lucky) / operations  to be  used with the usual commutativity and associativity

[fonograph]

I am on Khan webpages and cant find that test that tells me what my skill level is.Can someone please link it there?

[rx8pilot]

I am on Khan webpages and cant find that test that tells me what my skill level is.Can someone please link it there?

There is no such test. You simply start at a level that seems reasonable and see how you do. If you fly through and pass easily - move up to the next level. Keep doing that until you get to where you are presented with the material you do not know.

You are responsible for deciding where to start.

[CatalinaWOW]

Resistors are used in almost all circuits, so resisters are all there is to complex circuits.  NOT!  Same thing is true about algebra.  The tools of algebra are used in almost all mathematics, but there more to it than hiding behind complex symbols.  This is not meant to discourage anyone, but to point out that there is more to learn at the higher level of math.  Much has real, if occasional application to the real world.  And much of it is fascinating in it's own right. 

[IanB]

I am on Khan webpages and cant find that test that tells me what my skill level is.Can someone please link it there?

Did you try the tests I linked above? Can you answer them, or or they difficult? You should print them out and actually try to do them. That will tell you a lot about where you need to start.

http://www.bbc.co.uk/schools/gcsebitesize/maths/mocks/

[Mr. Scram]

There is no such test. You simply start at a level that seems reasonable and see how you do. If you fly through and pass easily - move up to the next level. Keep doing that until you get to where you are presented with the material you do not know.

You are responsible for deciding where to start.

There certainly used to be one, but they regularly fiddle with how things work.

[Syntax_Error]

Yes, there definitely was one or more in the past. I remember taking it on a profile I had and I had my kids take it as well. It was an adaptive test where the difficulty of the questions increased or decreased based on your real-time successful/unsuccessful answering of questions.

[Syntax_Error]

So I just created a new account, and literally the very first thing it presented me was a math quiz to judge where I am. It is called Mission Warm-up, and says "Complete your mission warm-up to unlock personalized practice skills!"

It is under dashboard: mastery challenge. Hopefully this helps you find it.

[rx8pilot]

So I just created a new account, and literally the very first thing it presented me was a math quiz to judge where I am. It is called Mission Warm-up, and says "Complete your mission warm-up to unlock personalized practice skills!"

It is under dashboard: mastery challenge. Hopefully this helps you find it.

Excellent - I never saw that before.

[Syntax_Error]

Now I just need to figure out how to jump to a more appropriate level... It quite literally starts at "The Beginning" as in learning to count from 0 to 20. 

EDIT: So after completing my sign-up by going to my email and clicking the link, I completed a profile and then noted two things:

1. On the progress tab, there is a dropdown to change the target material directly, but this is less useful than 2.

2. I clicked Home, and it asked me what grade I was in, and there was an Adult Learner option. Checking this then asked me what I wanted to learn. I checked five math options and two sciences (physics and electrical engineering) and two computer topics, and voila, I now have my curriculum.

[bsfeechannel]

In my antenna thread someone suggested learning Maxwell equations and I was sad becose I knew there is no way in hell with my current math skill to ever be able to understand them.

Now I'm feeling guilty.

 
 No,I am thankful you did it.Small dose of saddness is good if it stimulates the action that removes the problem.I should have learned math long time ago.If I wasnt sad about not being able to learn Maxwell equations,I would be procrastinating god knows how long.

Well, I'm glad that my comment has not discouraged you. I was afraid of that.

Math, like a good oscilloscope or multimeter, is an invaluable tool in the hands of a competent engineer.

Go ahead and never give up. It's worth the investment.

[TerraHertz]

Also fonograph, remember that you are very fortunate to have nothing preventing you pursuing mathematics. In contrast I have some 'interesting life challenges' that absolutely must be solved first, before I have any hope of success with long term ambitions.

[fonograph]

Can someone please help me solve mathematical problem? If there is circle with 16 cm diameter on grid of 1cm squares and we count the total surface area of all the squares that the circle goes through or are within the circle,then what is the worst case difference between the area of the circle and area of all the squares intersected or laying within the circle...

[IanB]

Can someone please help me solve mathematical problem? If there is circle with 16 cm diameter on grid of 1cm squares and we count the total surface area of all the squares that the circle goes through or are within the circle,then what is the worst case difference between the area of the circle and area of all the squares intersected or laying within the circle...

That's quite a difficult problem. Unless one of us knows the answer already, it would take quite some time thinking about it to come up with the solution. For example, I have no idea. I would have to spend ages thinking about it before being able to figure it out.

[helius]

The greatest difference (the worst case?) is the case with the maximum number of squares, so this is really a problem of how many squares you can fit under the circumference.

Each square is 1 cm², so the answer is of the form \$ n - 64\pi  \$ cm²

(since the area of a circle is \$ \pi r^2 \$ given r is the radius, and the diameter is twice the radius)

[IanB]

Yes, it's clear the total number of squares enclosed or touched is an integer, but given that the circle could have any position on the grid, how would you figure out the position of the circle that touches the most number of squares, and what that number is?

[helius]

There are probably only two cases worth worrying about, the case where the circle is centered on a grid square, and the case where it's centered on a corner between 4 squares.

In the latter case, the whole circle is inscribed in a 16 x 16 square grid. In the former case, it's clear the grid needs to be 17 x 17.
How many squares does it touch? You could find out using a compass, or use algebraic geometry and the circle's defining equation, \$ x^2 + y^2 = r^2 \$ . There will be a limited number of integral solutions, which are the points where the circle traces a grid corner, and you can fill in between them to see how many squares it touches.

The above equation in integers is a diophantine equation, and its solutions are the pythagorean triples.