*“Integer Solitaire” is free on this website for one week only. It’s an excerpt from Prealgebra & Geometry: Math Games for Middle School, available as an ebook at my bookstore (Thank you for cutting out the middleman!) and in ebook or paperback through many online retailers. Read more about my playful math books here.*

Many parents remember struggling to learn math. We hope to provide a better experience for our children.

And one of the best ways for children to enjoy learning is through hands-on play.

This game gives upper-elementary and middle school children plenty of practice adding and subtracting integers. It’s a fun challenge for older students and adults, too!

## Integer Solitaire

**Math Concepts:** integer addition and subtraction.

**Players:** one or more (a cooperative game).

**Equipment:** playing cards, large sheet of poster board (optional).

### Set-Up

Draw the four equations shown below on a sheet of poster board, large enough that playing cards fit in the blanks.

If you don’t have poster board, draw the equations on paper (or use the gameboard from my *Prealgebra & Geometry Printables* download file) so players can write in their numbers. You may want to slip the gameboard into a clear page protector or laminate the paper for use with dry-erase markers, to make it easier to move the numbers around.

Agree on which color represents negative numbers. Aces count as one, number cards at their face value. The jack, queen, and king are eleven, twelve, and thirteen, respectively.

### How to Play

Deal out eighteen cards and set the rest of the deck aside. Arrange these cards in the boxes on your gameboard. There are only fourteen blanks, so you won’t use all the cards.

Can you make four true equations? If so, you win.

### Variation

If you succeed with eighteen cards, try the game again with seventeen. Can you do it with sixteen cards? Is fifteen enough to make it work?

### History

Math instructor Kent Haines, who created this puzzle game, writes:

“I love this game because it doesn’t require a lot of supplies, can be played in fifteen minutes, and remains challenging even after a student has mastered integer addition and subtraction.

“I picked the starting amount of cards on intuition. I have played this game for five years with dozens of students, and I have yet to see a combination of eighteen cards that is unsolvable.”