3 Tips for Adding Quickly

What do speed reading and speedy arithmetic have in common? What’s the fastest way to come up with approximate answers to addition problems? And how can multiplication help you add faster? Keep on reading The Math Dude to find out!

Jason Marshall, PhD
4-minute read
Episode #224

Addition ProblemWhile I was out and about doing some holiday shopping this week, I realized that I somewhat unconsciously use several mental addition tricks to help me keep track of how much money I’m about to spend. After noticing this, I also realized that these tricks probably aren’t the obvious ones that people use all the time - which is why I thought I’d share them with you today.

In particular, we’re going to learn the connection between speed reading and speedy addition, the fastest way to add numbers when you only need an approximate answer, and how multiplication can speed up addition..

Tip #1: Just Do It (Don’t Say It)

Today’s first tip is simple to say, hard to implement, but extremely effective once you do so. Here’s the trick: Stop subconsciously talking yourself through mental addition problems. That’s it. Although, as I said, following this advice is easier said than done.

Stop subconsciously talking yourself through mental addition problems.

If you’ve ever learned to speed read—or tried to learn, as I have—you’ve no doubt come across the advice that you must stop subvocalizing as you read. I find this incredibly hard to do when reading, although some people seem to be able to do it. While I find it tough to do while reading, I’ve realized that I do it naturally when adding up a list of numbers.

For example, when tallying a list of numbers like 23, 17, 7, 12, and 31, my inner monologue is not something like:

23 plus 17 is equal to…uh…40, then 40 plus 7 is 47, then 47 plus 12 is 59, and finally 59 plus 31 is…um…90,

but is instead something like:

23, 33, 40, 47, 59, 90.

In other words, I don’t subvocalize what I’m doing - I just do it. In this case, I started with the first number, 23, then added the 10 from 17 to get 33, then added the 7 from 17 (noticing that the 3 and 7 add to form a convenient multiple of 10) to get 40, then the following 7 to get 47, then the 12 and 31.

The point is that I did each step without saying what I was doing to myself. Instead, I just did it. Once you get used to doing that—which, admittedly, does take some practice—you’ll find that cutting out the subvocalization gives your mental addition a huge speed boost. And, for me at least, it’s a lot easier to do this with addition than with reading.


About the Author

Jason Marshall, PhD

Jason Marshall is the author of The Math Dude's Quick and Dirty Guide to Algebra. He provides clear explanations of math terms and principles, and his simple tricks for solving basic algebra problems will have even the most math-phobic person looking forward to working out whatever math problem comes their way.

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