Have you played the math game, Krypto? This fraction activity is fantastic for problem solving, reasoning, and practicing fraction operations skills. I think your students will love it! Krypto is an activity I learned about at a conference where Dr. Lola May presented (in like 1993, I think!). I didn’t realize until a long time afterwards that it was a commercial game that could be purchased 🙂 I believe it’s also available as an app now.

I’ve used the game idea from time to time, following the rules as laid out in the book I got at the conference. Krypto can be played with whole numbers or fractions (and with positive and negative integers as well, I’m sure!).

## Playing Krypto With Fractions

**The rules are simple** (kind of like the “24” game):

1. Choose 5 common fractions, with denominators of halves, thirds, fourths, sixths, eighths, tenths or twelfths.

2. Students add, subtract, multiply, and/or divide the fractions to make the 5 fractions equal the target number of 1.

3. Students receive points for meeting the target number of 1.

- For example, if they reach the target of 1 using only 3 numbers, they get 300 pts
- 4 numbers = 400 pts
- if they use all 5 numbers, they get 1,000 pts.

You can set up the point system any way you’d like.

Krypto can be used as a team effort/team game or individual enrichment activity.

This math activity is a fantastic way to provide practice with all the fraction operations. It promotes problem solving and persistence.

## Fraction Activity Example

When I use this activity, I put fraction cards on the board and leave them for as long as I need (and move them if they get in the way!)

- One solution for this set of fractions in the picture could be 3/4 x 2/3 + 1/2 = 1
- This solution uses only 3 fractions, so that would earn 300 points.
- Another solution is 2/3 + 2/6 = 1; but that’s only 2 fractions. You might consider giving points for using just 2 fractions, until students get the hang of it.

Can you make the 5 fractions equal 1?

## Krypto With Whole Numbers

If you’d like to try Krypto with whole numbers, the directions are basically the same:

1) Choose 5 numbers (from 1-20)

2)Choose a target number between 30 and 50).

According to the book I received at the conference (yes, I still have it:-), computers at Berkeley, CA showed that a 5-number solution can be found 86% of the time when the 5 numbers and the target number are chosen randomly.

Example:

- Choose 3, 4, 7, 12, 14
- Target number: 42
- Solution (using 4 numbers): (12 – 4) x 7 – 14 = 42

What other solutions can you find?

If you haven’t used Krypto with either fractions or whole numbers, I hope you’ll give it a try.

Interested in more fraction and fraction operation content?

Check out the fraction program, **Fractions: From Foundations to Operations.**

You can also grab this free fraction operations math wheel (plus other fraction goodies) when you join the email community!