So much of our financial lives come down to certain numbers.

There’s the retirement figure you hope to get to so that you can retire and not worry about eating better than store-brand potted meat and rice.

We’ve got to guard our Social Security number. Although, based on the frequency of major data breaches, that number may already be compromised.

And of course there is the SAT-like number that has come to define our overall financial identity: your credit score. (Technically, you actually have more than one credit score, since there are several variations of the measure of our financial worthiness to become debtors.)

Pumping up your credit “number” should be a priority. The higher your score, the more likely you’ll get favorable lending terms, because the algorithms say you’re more expected to pay your debts.

A landlord is likely to ask for a credit number. A potential employer will want you to disclose it. Even a date, hoping to become serious, might judge you by your credit score. A Federal Reserve study found a link between a lasting relationship and good scores. Couples with similarly high credit scores tend to stay together.

So do you know your number? And more importantly, do you know enough about how the credit-scoring system works to boost your rating if it’s not measuring up?

If you’re not sure, pick up the Color of Money Book Club selection for this month, “Your Credit Score: How to Fix, Improve and Protect the 3-Digit Number that Shapes Your Financial Future” (FT Press, $26.99), by personal-finance author Liz Weston, who writes the syndicated column “Money Talk.”

Be sure to get the fifth edition. Why so many versions?

The credit-scoring world is complicated and ever-changing.

“Twenty years ago, you didn’t even have the right to know the numbers that lenders used to judge you,” Weston writes. “Today, you can get dozens of your scores online within seconds, along with detailed information about what goes into creating each one. Instead of having too little information, sometimes it can feel like you have too much.”

Weston, who also writes for NerdWallet.com, has put together a very informative guide to the underbelly of credit scores. Trust me, there is some stuff under the hood of this system that you need help understanding. In fact, she devotes a whole chapter: “Credit-Scoring Myths.” Here are some of the top myths she dispels:

Checking your credit report too often will bring down your score.

 You need to pay interest to get a good score.

 Credit counseling is worse for your score than declaring bankruptcy.

 Your score will automatically drop if you comparison-shop for rates such as before buying a car or applying for a home loan. (You actually have a window in which multiple inquiries won’t hurt your score.)

Last month, Chase Slate released the results of a study that found that 40 percent of Americans don’t know their number. Of those who do, 32 percent aren’t happy with their scores. Of those who are dissatisfied with their score, 82 percent would like to spend the year improving their rating.

In a report released earlier this year, Credit Karma found that more than two-thirds of people surveyed said they had made a major credit mistake before turning 30. They either overspent using credit, paid bills late or defaulted on a loan. Those actions can create tsunami-like forces that significantly drag down your score.

“How you handle your credit problems will have a huge effect not only on your credit worthiness but also on your financial future,” Weston writes in the book. “The wrong move can sink you further into debt, devastate what’s left of your scores, and put your entire financial life at risk. The right moves can help you claim out of the hole stronger, wealthier and more creditworthy than ever before.”

You’ve probably heard the radio ads from companies promising to “fix” your credit. Often that repair comes with a high price from several hundred dollars to thousands of dollars. Save yourself some money and frustration by studying Weston’s book. Fixing your credit is a doable DIY (do-it-yourself) endeavor as long as you have the right information. And “Your Credit Score” gives you just that.

If you’re new to the book club, we don’t meet in person. Just get the book and join me for the live online discussion. I’ll be hosting a chat about this month’s selection at noon on March 24 at washingtonpost.com/discussions. Weston will be joining me to take your credit-score questions.

Michelle Singletary can be contacted at:

[email protected]

Twitter: SingletaryM