Copyeditors are word people. We push away numbers as though they were plague-ridden. I make sure, then, to teach fact-checking math in my Copyediting III class. I want my students to become copyeditors who don’t blanch at the sight of an equation.

During the math lesson discussion this spring, several students had some great ideas about how to approach numbers, how to fact-check them better, and how to decide which tools copyeditors can use to work with numbers better.

**A Relaxed Attitude**

Success with numbers starts with a relaxed attitude. If you view math as something you’re not good at, you’ll dread the task and not do your best work.

“I think the most important thing about catching math errors has to do with being engaged with the text while copyediting,” wrote Emily Roberts. “Most of the math issues that crop up in nontechnical texts can be caught if you slow down and work through what is being said with numbers.”

Lisa Lord also had a good attitude with regard to math fact-checking. “I’m not especially gifted with math, especially more complex mathematics (I still have nightmares about 10th grade trigonometry) and complex equations,” she wrote. “But I also spent a number of years in a quasi-accounting role, and I found that I enjoyed that type of math. It was almost fun, like working on a puzzle that you know you’ll be able to solve, even if it takes a while.”

Lord went on to explain that math rules are fairly clear cut, and even if she doesn’t know them, “the answers are probably just a few clicks away.”

**Logic Is Your Friend**

Roberts listed several logic questions we can ask when numbers appear in the text:

- If a date and a length of time are given, is the math correct?
- Are fractions and percentages being used correctly?
- Do the numbers in charts, tables, and graphs make sense?
- Do they show what the author thinks they show?
- Are they arranged logically?

For calculations, I’ve long been fond of Excel. I may not trust my ability to perform a calculation, but I trust Excel’s. When I have to check a lot of numbers, I do so in a separate editing pass, entering my calculations on a spreadsheet. Then I can cross-check references in the text against the spreadsheet during the main editing pass. If I need to explain my thinking to the author, I can refer to and even share my spreadsheet.

Kurt Stolle recommended “diving in and getting some experience.” After a while, he noted, “it’s just another chapter in *CMOS* to check that you’re following the rules.”

**Beyond the Calculator**

“Numbers for any scientific formula [or] medical dosage … are particularly important because lives can literally be lost if there is a numerical inaccuracy,” reminded Laura Childs. Most manuscripts, though, “offer good explanations of the notations to use and basic formulas. There are also specific style guides and dictionaries that provide detailed guidance as well,” she said.

For understanding math better, Rachel Bosch recommended *A Mind for Numbers: How to Excel at Math and Science*. The book focuses on the number of ways there are to solve the same problem. Learning to think creatively about math problems can help copyeditors solve them in a way that works for them.

In addition, I share these links with my students to use in their work:

- Wikipedia’s metric prefix page
- MegaConverter 2
- Percentage Calculator
- Online Conversion
- EditTeach.org’s Math & Numbers page
- RobertNiles.com’s Statistics Every Writer Should Know page

Even if copyeditors generally aren’t very good at math or don’t like numbers, there’s a lot we can do to ensure that the numbers in our manuscript are as accurate as the words. Follow these tips and you’ll become a math-checking star!