The game is mainly for primary school grade three，corresponding the third grade fourth unit of primary school mathematics of Human education--Mental arithmetic multiplication.You have learned about nine nine multiplication tables and multiplication of single digit and multi-digit.Have you mastered the previous knowledge？We have calculated two digits by two digit arithmetic using the knowledge learned here. Hit the spirit, and lets go into different worlds and experience different training methods.In the world of games, learning becomes easy and fun! QD learn aims at teaching through lively activities and happy learning.