Ann Marie Stephens is the author of the Arithmechicks series as well as a contributing writer for Kwame Alexander's The Write Thing. She was an elementary school teacher for more than 30 years.

Jenn Harney is an illustrator and toy designer. She is the illustrator of Probably a Narwhal, "Smelly" Kelly and His Super Senses: How James Kelly's Nose Saved the New York City Subway, and George Washington's Spectacular Spectacles, among others. Her work has also been featured in Highlights magazine. You can find her on Instagram at @jennharknee.