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Stanford game entertains while teaching early math concepts

Harper Franklin plays Critter Corral
Harper Franklin plays Critter Corral
Screenshot from Critter Corral
This game is available on iTunes.
Screenshot from Critter Corral
This game is available on iTunes.

Stanford game entertains while teaching early math concepts

Critter Corral, a game for iPads developed at Stanford, lets kids count bugs’ feet, serve apples to raccoons and play with trains.

Harper Franklin faces a big question. While playing the iPad app Critter Corral, he had selected “2” when asked which number of cars were needed to fill three spaces between an engine and a caboose. “Can you fix it?” the app asked him.

He presses a small finger once on a “+1” button, and the app explodes with applause. Harper, 4 years old, responds with a big grin.

 He’s clearly engrossed with Critter Corral, a game developed at the Stanford University School of Education that uses animals in a Wild West theme to help teach 4- to 6-year-olds early math concepts.

Able to count confidently to number 5, Harper hadn’t learned numerical symbols when he started playing the app. But after 20 minutes of counting bug feet, eyeballing train cars and deciding how many apples to serve a group of raccoons, he started to recognize 1, 2 and 3.

“It was fun,” Harper said as he put on his raincoat and headed off to preschool after giving the game a trial run earlier this week.

Kristen Blair, a research associate in the education school’s AAA Lab, headed the team that developed Critter Corral, which took a year of work and funding from the Wallenberg Foundation. It is available for free for the iPad. (Download it from

The researchers tested it with kids at local preschools, as well as Blair’s own daughter, before they released it in mid-December. They’re hoping it’ll become popular with an even wider audience. After all, it doesn’t cost anything, and, it's very entertaining.  “All our pilot testing indicates that children love it.” said Daniel Schwartz, professor of education and head of the AAA Lab.

Stanford AAA Lab researchers are hoping to prompt a plethora of downloads, both because they believe it’s a good tool for teaching young children math, and because it will help them with their research. “We want people to use it, and we want to learn more about how kids are solving problems,” said Blair. It’s her voice on the game explaining the problems, counting and asking questions.

Ensuring that preschool children are grounded in math concepts — beginning addition and subtraction as well as geometry — is critical, as those who enter kindergarten with better mathematical understanding outperform their peers. Early math skills are connected not just to better math performance later on, but also to improved reading and possibly higher high school graduation rates.

Yet, as Blair noted, few math games for preschoolers promote the kind of reasoning Critter Corral does. For example, the game lets children see how far off their answers are and gives them an opportunity to fix them, instead of just signaling “right” or “wrong.” “This helps the children really get to the ‘meaning’ of numbers,” she said.

 Blair added that, in Critter Corral, “We integrated multiple representations of numbers. Instead of just the numeral 3, we have three dots, a length of 3 units, a third position in a line of cars.”

According to Schwartz, children must link these concepts if they are to gain a strong math sense. “Young children do not always know that if you count up the number of objects in a pile — ‘1, 2, 3’ — that the last number also stands for the total number of objects,” he said. “The game helps children connect these different ideas of quantity.”

As the 4-to-6 set play the game, AAA Lab researchers will be able to gather information — without knowing who it’s from — on how children respond to problems. They can use that information to improve the game, if, for example, players seem to get stuck at a certain point. It will also help inform the lab’s understanding of math learning.

“We are conducting efficacy research to see how well it helps children learn early number concepts and prepares them to keep learning more advanced concepts,” Schwartz said. “We can analyze the anonymous data to help determine which parts of the in-game experience seem to be helping the most — for example, by tracking where children exhibit a faster rate of improvement.”

The information automatically gets tracked when players answer a question. The answer they gave, the time it took, and the level and game they were playing, among other things, automatically gets sent to a server. “We randomly generate an alpha-numeric code for each player that is added to the data sent to the server so we can follow their progress over time, but we don't know who a player is or where they're from,” Blair said.

The game is freely available for iPad users on iTunes at Once the researchers have tweaked the game, they plan to introduce it to other platforms, possibly cell phones.

The team that developed Critter Corral included graphic designer Jamie Diy, instructional designer Heidi Williamson and researcher Jessica Tsang, along with Blair and Schwartz. Blair is a graduate of the Learning Sciences and Technology Design program at the Stanford University School of Education, having earned her PhD in 2009.

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