Add & Subtract to 20: Student Workbook (Grades 1–2)
Add & Subtract to 20 is a research-based workbook that helps children master addition and subtraction within 20 without tears or rote memorization. The book is currently available on Kickstarter and will be published in March 2026. It is designed around the calculations that typically cause the most difficulty in early elementary grades—especially problems that “cross ten,” such as 8 + 7 or 12 − 5—and provides a method that truly works.
Each of the 8 lessons begins with a short story: helping Mary count mandarins for a party, building magical castles with Cindy’s colored pencils, or going on quests on an island of mathematical treasures. Children are not just “doing exercises”; they solve meaningful problems for the story characters and gradually overcome difficult calculations. Instead of memorizing ready-made rules, students explore with cubes and visual models, discover strategies through hands-on practice, and understand why their methods work.
The workbook is based on P. Ya. Galperin’s theory of step-by-step formation of mental actions: students first act with real objects, then work with diagrams and pictures, then speak each step aloud, and finally compute quickly and confidently. This approach makes misunderstanding unlikely because every idea grows from concrete experience and clear visual support. After 8 lessons, children confidently add and subtract within 20, find answers without counting on fingers, and feel proud that “I figured it out myself.”
The book is ideal for 1st–2nd grade students who struggle with crossing ten, for school readiness, homeschooling, extra practice, or summer learning. It offers over 150 varied tasks, bright illustrations, ready-made diagrams and algorithms, self-assessment scales, and practical materials for modeling. Add & Subtract to 20 is an investment in your child’s mathematical confidence, logical thinking, and long-term success in learning.
Authors of Add & Subtract to 20: Student Workbook
Teaching Philosophy
“Mathematics is the creative language that explains our world,” Iryna says. Drawing on experience in New Haven public schools, after-school programs, and her own studies at elite STEM boarding schools (Kolmogorov Physics-Math School 18 and Kyiv Lyceum 145), she crafts interdisciplinary lessons that let students explore ideas, connect fields, and build lifelong confidence in STEM.
The Ukrainian-language PDF edition of the book will be available starting March 2026.
Рахуємо з переходом через десяток
Математика без сліз та зубріння!
Книжка виходить англійською мовою в друкованому та електронному форматах. Окремо доступна україномовна версія в електронному вигляді.
Our book, Add & Subtract to 20, is decorated with beautiful Petrykivka painting—a traditional Ukrainian folk art style.
PETRYKIVKA WORKSHOP
In support of the book, we’re hosting a series of Petrykivka workshops for families and the community.
Visit the workshop page to see the schedule, browse photos from past workshops, and learn what to expect:
Learn more →
Telerom students shine at the 2025 International Math Competition!
Timothy Yankovsky (Grade 2) 🏆placed 4ᵗʰ in Connecticut and 7ᵗʰ nationwide🏆 — an amazing achievement!
Why We Teach the Way We Do
The world is changing at a dizzying speed. The World Economic Forum noted that “more than half of today’s primary-school students will work in professions that do not yet exist” (Davos, 2016). Therefore, flexibility of thinking, the ability to solve non-standard tasks, and the capacity to use their full intellectual potential are especially valued. These skills will be the focus of our course.
We solve real math together — working problems out loud, modeling multiple strategies, and turning mistakes into “aha!” moments.