Another Important Key to Problem-Solving

Write down ~everything~

Very often I see students struggling with confusion when they try to solve a word problem all in their head.
It is so common, it's amazing. First of all, nobody says you have to produce the answer by just looking at the problem.
This is what happens, they read the problem, they understand the first sentence, or the first few sentences, and they are already asking themselves: "How do I solve this?" "What do I do with these numbers?" "What formula do I apply?" "What operation am I supposed to perform?"
They are obsessed with the idea of taking action steps. This is the first obstacle.
As soon as they come up with an idea about what to do, they start doing it, they start performing the operations, all in their head.
Then they get a partial result, and they immediately jump with that result into the next operation, without writing down anything. It's just unbelievable!
When I see them doing this, I tell them: "You are using your mind as a calculator and as a piece of paper at the same time. Don't waste energy like that."
For the average person, the mind can be much more effective as a calculator than as a piece of paper. The short-term memory that stores numerical results from previous calculations is very volatile.
When you try to use your head to do the operations and to remember the results at the same time, you are headed for trouble and confusion.
Let's say you make a mistake. If you write down all the steps of your calculation, and don't erase anything, you are much more likely to catch your own mistake when you go back and check your steps.
If you don't write down anything, you won't even remember what operations you performed, let alone catch a mistake.
So, write down everything, not only the partial results from each operation, but the whole calculation.
Write down not only the calculations you perform, but the ideas that made you perform those calculations.
Write down everything, every single step, all of it, your ideas, your examples, the formulas you are going to use, everything.
You will be amazed how easy the process becomes when you create this habit of writing down everything as soon as you think of it, and not erasing anything.
Even with mistakes, in the end it works better just to mark them with a red circle, and rewrite the correct expression somewhere else in the page, instead of erasing them. Many times mistakes are useful for reference.
As a general rule, the more you write, the better. The more you write, the less stress you put on your mind and the easier the process becomes.