Math facts that finally stick — in 10 minutes a day.
Proven learning methods meet playful stories to help young learners master essential math facts with confidence.
Get a free digital assessment to see where your child stands today. The workbook is available now — get your copy.
Watch the trailer
Meet Reti — and see the adventure in 30 seconds.
A peek inside Reti the Yeti: Adventures in Sumtopia — the math workbook kids actually ask for.
Build a strong foundation for math success — one fact at a time.
Math facts are being left out of many classrooms today. Without that fluency, kids lose confidence fast. Reti helps you close the gap in 10 minutes a night.
Closes the facts gap
Short, focused practice teaches the facts schools often skip — so nothing gets missed.
Builds real confidence
Fluency turns math from a struggle into something kids feel proud of.
No screens, no stress
Paper-and-pencil practice that sticks, without another login or glowing device.
A new kind of math workbook
- A story kids follow — save Sumtopia with Reti
- Addition & subtraction through 10, taught systematically
- Short, winnable pages that end on a high note
- Built by a teacher, tested on real elementary kids
"Fluency with math facts is one of the greatest determining factors of confidence in math."
Sabrina Soper, teacher & founder of Supernova Kids
Supernova Kids is an educational publishing company for elementary-aged kids, founded by a credentialed teacher and educational therapist. We make math story workbooks starring Reti the Yeti that build math fact fluency in about ten minutes a day. Meet the teacher behind the books →
Questions parents ask
Math fact practice, made simpler
What is Supernova Kids?
Supernova Kids is an educational publishing company founded by credentialed teacher and educational therapist Sabrina Soper. We publish math story workbooks for K–5 kids, starting with Reti the Yeti: Adventures in Sumtopia.
Who is Reti the Yeti?
Reti the Yeti is the friendly character at the heart of the Supernova Kids books. Kids follow Reti through Sumtopia while learning their addition and subtraction facts. Reti's name comes from "not yet" — the idea that a fact you don't know is simply one you haven't practiced enough times.
Who writes Supernova Kids workbooks?
Sabrina Soper — a UCLA graduate, credentialed teacher, and certified educational therapist who ran The Learning Space tutoring center for over a decade.
Where can I buy Reti the Yeti books?
Reti the Yeti: Adventures in Sumtopia is available from the Supernova Kids shop — available now at supernovakids.com/shop.
What are math facts?
Math facts are the basic addition, subtraction, multiplication, and division equations children learn to recall accurately and efficiently. They are the foundation for more advanced math.
How can I help my child learn math facts without screens?
Use short paper-and-pencil practice, teach one strategy at a time, model problems with everyday objects, and play simple games with cards or dice. Keep it encouraging and end with a win.
How long should children practice math facts each day?
About ten focused minutes a day is enough when practice is well sequenced, consistent, and matched to the facts your child needs to learn.
Why is math fact fluency important?
Fluent recall frees your child's working memory for multi-step problems. Instead of spending all their energy counting, they can focus on understanding, reasoning, and building confidence.
Are you Reti?
The workbook is available now — plus grab a free digital assessment to check where your kids are currently at.
Buy the book