Keep your kids on their toes with this Educational Insights Math Trekker, which is perfect for on the go. Portable, electronic math game for addition and subtraction practice Small 3" unit with LCD screen 0-9 number buttons Age: 6 years & up Requires 3 replaceable AG13/LR44 (included) Imported Model no. 8501 Size: One Size. Color: Multicolor. Gender: unisex.