Round 'Em Up

This week's game was invented by Tracy Proffitt, who is one of the hosts of the lovely Math Before Breakfast podcast. If you're a teacher, by the way, definitely check out Tracy's podcast! They do a great job of keeping a conversational vibe while also being well-prepared and thoughtful on their topics. And the show notes are a treasure trove of great resources, activities and games!

Anyway, I was asking around for a game that could help kids play with rounding multidigit numbers, and Tracy sent me her game. We've decided to call it Round 'Em Up, and I've even made some rudimentary game cards if you want to print and play. 

By the way, Tracy and I have each play-tested multiple variations of this game, but we're not done! If you have any ideas while you and your kids play, please reply to this email with your thoughts!

How to Play

Round 'Em Up is a two-player game. To start, take the papers with the numbers from 0 to 1000 and place them face-down. Each person takes turns drawing five cards (there will be one left over. You can either give this one to your kid as an advantage, or set it aside)

These numbers represent sheep that have escaped from your farm. You need to round 'em up! So how can you do this?

Shuffle the Digit Cards and draw three at random. (If you don't want to print the cards, you can use the 1-9 cards from a pack of cards and discard the 0 sheep. Or if you're a weirdo like me, use the ten-sided dice you happen to have lying around)

The three digits you choose can be arranged in any order. The goal is to arrange them so that the number, when rounded to the nearest hundred, matches one of your sheep! 

If you can arrange the digits to round to one of your sheep, you get 1 point. If the number you create is within 20 of one of your sheep, you get 2 points. Within 10 and you get 3 points.

So let's say you have the 200, 300, 600, 700, and 1000 sheep. You draw the digits 1,5, and 7. 

You could arrange them to 157 to round up to 200, or 571 to round up to 600, or 715 to round down to 700. Any of these would be a valid move, but the last one is within 20, so you would win 2 points!

You must make a three-digit number, even if it doesn't round to one of your sheep. So watch out, because if it rounds to your opponent's sheep. they get a point!

You can play as many rounds as you want, and whoever has the most points at the end of the game wins.

Where's the Math?

Clearly, Round 'Em Up is a math-based game. I think it's a wonderful game to try out, though, because it gives your kids a sense of what rounding actually is.

Most kids learn the "five and up, round up" rule in math class, but there is a deeper idea that is often missed: rounding is about closeness. The rule derives from the concept, not the other way around. 

So when your child is arranging their three-digit number, they are trying to make numbers that are as close as possible to their targets. The closer they are, the more assured they can be that they'll score a point. The game helps kids make the connection between rounding and closeness explicitly, by awarding bonus points for closer and closer numbers.

The game can be adapted to rounding with tens, thousands, or even decimals. Each adaptation maintains the big idea: Build a number as close as possible to your target.

But Tracy and I are wondering - where else can this game go? What rules would you change or add? How would you make it playable by three or more players? So download the game file, try it out, and please send me your ideas! We'd really appreciate it.