I am a fast writer. Pencil down, answer out, next. The problem is that my pencil is faster than my reading, and most of my mistakes happen in the gap between the two.

So now I do one thing before I write anything: I read the expression out loud. Quietly is fine. Under your breath is fine. Mouthing it in class is fine. It just has to be actual words, not a glance.

Why out loud works

When you glance at an expression, your eyes jump to the numbers and skip the small stuff. The small stuff is the signs. When you say it, you cannot skip anything. Every minus has to come out of your mouth as a word.

Glance: six a, two b, five. Out loud: “six a, minus two b, plus five.” Saying “minus two b” as one chunk keeps the sign glued to the second term, which is −2b.
6a − 2b + 5

The five seconds

It is the same five seconds the videos give you on a Think Break. Here is what I do with them.

One: say it the long way. “Three times x,” not just “three x.” “Minus” when something is being subtracted. “Negative” when a number is below zero.

Two: touch every minus sign and say which number it belongs to.

Three: say what you are doing first. Not the answer. Just the first move.

What it catches

Here is one that nearly got me. Evaluate 2m + 5 when m = −3. Glancing, I almost wrote 2 − 3 + 5, which is 4. Wrong.

Out loud: “two times negative three, plus five.” “Times” reminds you the 2 is multiplying. “Negative” reminds you −3 is one number, so it goes in parentheses.
2(−3) + 5−6 + 5= −1

And another: 18 − 5 + 2. Glancing, it is tempting to add the 5 and the 2 first and get 11. Say it, “eighteen minus five, plus two,” and the little pause after “five” keeps the minus with the 5. Left to right: 13, then 15.

Bandit note: I thought this would slow me down. It does, by five seconds. Finding a dropped minus sign three lines later costs me a whole restart. Five seconds up front is the actual speedrun.

The part to remember

You do not need to say it out loud forever. After a while the words start running in your head on their own. Until then, give them a voice. Most of my sign errors now get caught right there, before they ever reach the paper.

The notebook version: Before you write, say it. Times, minus, negative: every sign out loud, every minus attached to its number. If you can say it right, you are far less likely to write it wrong.