I had to struggle with dyslexia. I was good at mathematics, but useless at formulas. I had to understand the formula fully otherwise it didn't make sense to me. So at school and university, I always did much better at higher math rather then the standard math as the standard math course was all about memorizing equations.

Still type with letters reversed, and sentences that sometimes don't make sense, but I have improved gradually over the decades.

In many ways, a slide rule would be good as it is all about thinking in sizes rather then numbers, but it does take a lot of mental discipline to get good at a slide rule. The accuracy of a slide rule is easily good enough for an average electronic design. The thing you realize from a slide rule is that often two digit resolution is all you need. If you make mistakes entering 5 digits or more, then reduce the digits down to a point where it is easier to check for an entry error.

My recommendations is for a calculator, it has to be an HP RPN calculator. Algebraic calculators at first glance appear simpler to use but in reality they are far more mentally difficult to use and are suited for the literal mind rather then the dyslexic mind. The basics of RPN is that you have to get the numbers first before you even think about what operation you are going to apply to them. I mean it is dumb thinking about the divide operation before you have the two numbers you need for the division already in the calculator. Literal minds might not understand that, but I think you might. You can do things one step at a time and you never need to touch literal mathematical constructs like brackets again.

Currently the best calculator ever made - the HP15C - is being re-offered by HP in a limited release. It is the perfect shape, size and it has just the right level of complexity so you can remember how to use it without needing to be a genius. The calculator is in landscape mode which is the best way for a calculator to be arranged. It has the best calculator keyboard available. Battery is a few button cell batteries and they last forever. I still have my HP11C (slightly simpler version) from something like 30 years ago, and it still works perfectly. I know people who stock up on these for the future.

Now onto design. I have written about it before, but it is amazing how much design you can do using vary basic formula - ohms law, basic formulas for inductance, capacitance. You can do a first pass model of a transistor as a device that in linear mode will do anything at the collector to make sure the emitter base voltage is 0.65 volts. Sounds too simple, but most of the time, it is all you need for a first pass design. Then you can add corrections for more accurate approximations and still not touch the textbook equations for a transistor. Using the basics, I often end up doing my own calculations and coming up with the same results as the data sheet formulas.

In fact I see a great big equation in the datasheet, I am likely to think "how can I trust that?" and just ignore it. I need to understand my design.

Being able to use Laplace transformations is one of the big breakthroughs, but there is a catch. Laplace Transforms are the key to AC circuit design. The initial explanations and derivations unfortunately are horrendous for a dyslexic, but once you understand that an inductor = sL and a capacitor = 1/sC, and see how to use it, you dump the textbook stuff totally. Trouble is without wading though the textbook derivations of the Laplace transform results, I am not sure how you can get any understanding of it.

Now as far as learning the mathematics, there is a site that I think is one of the most brilliant sites I have seen on the internet, outside the eevblog.com site of course.

http://www.khanacademy.org/Give it a go. So basically if you can get really, really good at using the really basic equations (and understand them at the same time) you can go a very long way.

Richard.