Yonjuu: Playful Math Card Games for Kids

Here is an animated tutorial explaining the rules for Level 1 of Yonjuu. The goal is to strategically combine cards to reach a total of 40, helping players develop number sense and quick mental math skills.

Ready for a challenge? This video explains Level 2 of Yonjuu, which introduces trump cards. This feature adds a layer of strategic complexity, teaching players about integers and negative numbers in a dynamic and engaging way.

Before starting a game, it's great practice to find "partners of 10." My son Kai demonstrates how to quickly group cards that add up to 10, a foundational skill for building math fluency and speed.

What if there are no easy partners of 10? Here, Kai explains a key strategy: making a 10 by borrowing from another card. This technique, known as bridging, is a powerful mental math strategy for addition.

Yonjuu cards are a great tool for moving beyond rote memorization. This video shows how to use the cards to visualize multiplication as "groups of," helping learners build a true conceptual understanding of the operation.

The visual design of the Yonjuu cards makes abstract concepts concrete. This tutorial demonstrates how to use the cards to teach addition and subtraction by physically grouping and comparing the quantities on each card.

Building number bonds is a critical early math skill. Watch as a young learner uses the Yonjuu cards to discover all the different pairs of numbers that make five, reinforcing her understanding of part-part-whole relationships.

Here is another example of a child practicing number bonds to five with the Yonjuu cards. Consistent, playful practice like this builds a strong, intuitive sense of numbers that serves as a foundation for all future math learning.

Making ten is a cornerstone of number sense. In this clip, a child practices identifying pairs of numbers that add up to ten, a skill that is essential for mastering addition, subtraction, and the base-ten system.