Description: 【Math Learning Tool】Additive Decomposition Slide Ruler features a sliding number breakdown function, great for learning addition and subtraction, practical and multifunctional. 【Digital Decomposition Ruler】Number Matching Ruler is designed with addition and subtraction within 10 on the front side and and within 20 on the back side, and smooth pushing and pulling. 【20cm Straight Ruler】Math Learning Digital Decomposition Ruler is designed with length 20cm/7.87inch, can also be a 20cm straight ruler to quickly underline and mark key points. 【High Quality Material】Digital Decomposition Ruler is made of premium PS material, with fine texture, comfortable to touch, durable, lightweight and long using time. 【Wide Applications】Addition and Subtraction Calculator Numbers Matching Ruler is widely suitable for kids, child, children, boys, girls, home, kindergarten, school, classroom, etc. Specification: Material: PS Size Chart: Length: 20cm/7.87inch Package Includes: 1 Math Learning Digital Decomposition Ruler Note: 1.This is not infant toy, please take away from children to avoid eating. 2.Please allow slightly errors due to manual measurement and different monitors.