Math basics › When you're stuck
I keep making small mistakes
They are not careless, they are speed
Nearly all of them are dropped minus signs, a term left behind, or distributing to only the first thing in the bracket. Slow down at exactly those three moments.
One line, one change
Do a single thing per line. Doing three steps in your head and writing the result is where errors live, and it makes them impossible to find afterwards.
Keep the equals signs lined up
A tidy column down the page is not neatness for its own sake. It is how you find your own mistake in ten seconds instead of five minutes.