This may seem basic but it is a very common problem ...
In algebra you need to ensure each of your numbers, letters and symbols are distinct from each other. Otherwise you risk misreading your own writing, particularly in a time-pressured situation such as an exam.
Everyone’s handwriting is different, and only some of the symbols will be prone to muddling for you. Look at the table to your right to see some of the common lettering muddles that happen in mathematics.
Look across your letters, numbers and symbols - are there any that look too similar to each other?
The solution is to change the way you write some symbols.
Any tweaks you use to make symbols distinct will likely not be part of your normal handwriting, but used only for algebra – that’s expected. After a while they become habit, so practice your new symbols at every opportunity. This will reduce errors in your maths exams (and science exams, and others too).
Another related problem is attempting to overwrite a symbol with a new symbol when an error is detected. This can cause misreading and hence new errors. A very common example is attempting to change a plus sign into a minus sign. It is easy to go the other way (change a minus to a plus), but changing a plus to a minus is simply asking for trouble – it is always better to cross out the old symbol and write the new symbol separately. This is also the case for numbers and letters.
Some students regularly miss negative signs on numbers. A good solution is to surround the negative number in parentheses, which emphasises the negative nature. For example: \(-8 + 7 - -9 = 8\) versus \((-8) + 7 - (-9) = 8\)
If your writing becomes cramped, it is easy to misread. Take space to write out symbols clearly. Saving paper is not worth sacrificing exam marks (or miscalculating the strength of a bridge or pressure of a reactor, or …).