It's Not Magic, it's Number Sense! | exSTEMsions

## Magic with numbers

Do you know people, who, when you are out to dinner, effortlessly compute the tip, or quickly know how to divide up the bill between everybody at the table? You’ve seen them: the ones who can add in their heads, who know how much change they should get when they pay in cash at the store (yes, people still do that), or easily know how long it will take to drive a certain distance at a certain speed. What do these people have that makes them seem so magical? They have number sense. Yup. That’s it. Maybe you are one of these magical people. Maybe you aren’t, but wish you were. Here’s the thing: number sense, just like everything else in math (and in life) is something that we get better at with practice. It’s a learned skill, and anybody can learn it.  Yes, even if you’re one of the many of us who like to say “I’m not good at math”, you CAN be good at it, if you just practice.  Believe in yourself, leave your fear at the door, and clear out a little “math time” in your day, and you will be able to be one of those magical people!

## Practice builds number sense

Of course, you might be thinking, “Okay, great. I can practice, and maybe add more quickly in my head. So what? I have a calculator!” This is true, and I don’t entirely disagree. However, being able to quickly divide the check between friends is only ONE of the ENDLESS ways in which good number sense can be beneficial to us in so many different situations. Don’t believe me? Take a recent problem, about jelly beans in jars. This was a seemingly uncontroversial little problem, which only asked us to compare the proportions of beans in different jars. However, something quite strange occurred at the end of the problem, where the big skill required to actually make sense of the strange occurrence was - ta-da! - number sense! Often, when strange things happen in math, having a good grasp of how and why numbers work can help us to take a second, deeper look at the strangeness, and figure out that it’s not so weird after all. If you aren’t as comfortable working with numbers, it can be more challenging to tease the relevant pieces of information out of a problem when you reevaluate it.

## Why do we need number sense?

Number sense helps us do day-to-day tasks more easily, like plan a route for a bike ride, organize our time, pay for a meal, or cook a meal (ever needed to halve, or double, a recipe?). It also helps us make sense of answers to problems that seem, at first look, unexpected, or maybe even incorrect. Being comfortable manipulating numbers frees us to actually think about why the numbers are doing what they are doing, and what that means for the conclusion of the problem. These are just some of the reasons why having strong number sense is good for us. There are so so so many more... but I will resist listing them, since this is a blog, not a book! Having good number sense serves us in many ways. And, luckily, it’s something we can ALL get better at (no matter how strongly you believe numbers aren’t your friends). Like everything else in life, it just takes practice!

Find this post interesting? Follow the blog using the link at the top of the page to get notified when new posts appear!