*Photo by Håkan Dahlström via flickr.*

**Math concepts:** addition and subtraction within 100, logical strategy

**Number of players:** 2 or 3

**Equipment:** printed hundred chart (also called a *hundred board*) and beans, pennies, or other tokens with which to mark numbers — or use this online hundred chart

## Set Up

Place the hundred chart and a small pile of tokens where both players can reach them.

## How to Play

Allow the youngest player choice of moving first or second; in future games, allow the loser of the last game to choose. The first player chooses any number from 1 to 15 and places a token on that square of the hundred chart.

On each succeeding turn, the player adds either 5, 10, or 15 to the most recently marked number and places a new token on his sum. Play alternates until no more tokens can be placed.

## Endgame

The player who places the last legal token (on one of the squares from 96-100) wins the game.

## Variations

**1 — **Allow players to add any number from 1 to 20 on each turn. The player who reaches 100 wins the game.

**2 — Count Down:** Start at 100 and subtract 5, 10, or 15 per turn. The player who reaches zero wins the game.

**3 — Mental Math:** Try the game (or either variation above) without a hundred chart, keeping track of the numbers in your head.

## Comments

Nim is a traditional folk game of uncertain origin (similar games are played in many places around the world), and it has always been a favorite at our Math Club meetings. This version of Nim gives young children a chance to build fluency with double-digit arithmetic, an important foundation for their future study of mathematics.

This post is an excerpt from my book *Addition & Subtraction: Math Games for Elementary Students*, available now from your favorite online book dealer.

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This looks like a fun game to play. Thanks, I think that I’ll give this a try w/my kids.

Thanks! I’d never have thought of playing Nim on a hundred chart. There are lots of potential variants.

I’ve made one up to play with my six year old (she already does two-digit subtractions in her head, so this will just be a bit of fun for her). I’ll toss it in our big box of games.

I think that my 1st grader will really enjoy this and we’ll take it over to our friend’s house on our combined-class days for game time.

I can’t wait to try this with my first grader! We’ve used a hundred chart before and am glad to have more activities to do with it.

I enjoyed playing the games your posted yesterday together with my friends so I am back to learn more of the games you posted and I think this one is also a fun game.

Hi, thanks for this, it looks fun. Have you thought of adding an image to this post – a hundred square maybe – to make it easy to pin on Pinterest? (I tried but nothing to grab!)

Thanks for the suggestion, Lula. This is an old post, before I learned much about images and blog formatting. I really should go back and add images to several “golden oldies”, I suppose — anyway, I fixed this one.

Yes it did occur to me that this particular golden oldie is 5 years old! I barely knew what blogging was back then! It’s great that you’ve got so many wonderful resources going back so long

Five years seems like “forever” in internet time. I’m glad people are still finding my posts useful!

I started blogging in 2006, I think (at least, my archives go back that far), and moved to WordPress.com at the end of that year. I transfered posts related to my family with dates intact, but I revised and reposted most of my mathy games and articles over the next year or so. Then, as I learned more about blogging, I went back and added headings and other formatting to make things easier to read. Today I’m adding images to the To-Do list, but it will probably take ages to finish that.

If you find any other posts you’d like to see an image on, just let me know!