Sturdy Numarkasten! This "see, touch, and understand" educational material is perfect for Montessori and STEAM learning to eliminate stumbling blocks in arithmetic. My children (2 and 4 years old) actually use this! ■ Features of this product ・Sturdy resin case ・The back of the box is engraved with the golden ratio ・The size of the box itself is also the golden ratio. ・Slide-type lid that clicks into place ・By sliding the lid only halfway, you can hide how many balls are on one side ・You can roll the balls with the lid closed ■ Contents ・Numarkas body [Brown] ・Balls [Light blue marbles] Total 20 Size (approx.) Width 15cm, Length 10cm, Height 3cm Numarkas Early childhood education Educational toy Nature Science Please refrain from purchasing if you are concerned about the details, as this is a sale by an amateur. We offer discounts for multiple purchases and repeat customers, so please comment. Popular keywords... Shichida method Type... Numbers