Sturdy Numarkasten! This "see, touch, and understand" educational material is perfect for Montessori and STEAM learning to eliminate stumbling blocks in arithmetic. ■ The Difficulty of Subtraction with Borrowing For example, when subtracting with borrowing, like "12 - 7," how do you teach a child? The general method is to calculate "10 - 7" and then add the answer "3" to the "2" in 12. However, this has a problem: it involves two subtractions and one addition in a single calculation. ■ What is a Ten Key? This is where ten keys come in handy. A ten key is a number that, when added to a given number, equals 10. The ten key for 7 is 3, and the ten key for 6 is 4. Children who are good at math actually grasp this as an "image." In other words, they instantly know that the ten key for 4 is 6, and the ten key for 2 is 8. You might think it's just doing 10 - 6 or 10 - 2, but it's different. The important thing is that it's "visualized for instant understanding." Then, even in the calculation of 12 - 7, they can instantly see that they should "calculate 2 + 3." The calculation is done only once. ■ Train Ten Keys Visually with Numarkas The key is to visualize numbers and get off to a quick start. Math is a cumulative subject. If you stumble at the beginning, it's difficult to catch up. Conversely, if you can instantly judge ten keys with an image and solve problems faster than other children, it leads to confidence and further improvement in grades. Subtraction with borrowing is the first hurdle. I strongly recommend visualizing ten keys. ■ Features of This Product ・Sturdy resin case ・The golden ratio is engraved on the back of the box ・The size of the box itself is also the golden ratio. Mathematical beauty at your fingertips! ・Slide-type lid that clicks into place ・By sliding the lid halfway, you can hide how many beads are on one side ・You can roll the beads with the lid closed ■ Contents ・Numarkas body [Silver] ・Beads [Yellow marbles] + Add 10 more beads for 200 yen. Please comment before purchasing. Size (approx.) Width 15cm, Length 10cm, Height 3cm Numarkas Early childhood education Educational toys Nature Science Please refrain from purchasing if you are concerned about the details, as this is a private sale. Discounts are available for multiple purchases and repeat customers, so please comment. Popular keywords... Shichida method Type... Numbers