A unique puzzle game where players use concentration and memory to find same-color Oops Groups Express puzzle pieces. Win the game by being the first to build a train with four number cars in correct sequence and identify the one mistake on each car, earning a green light to move forward. Game includes suggestions for extending and supporting the game and reproducible worksheets that align with game´s educational targets. Provides engaging interactive math activities to address critical PreK - 1st grade expectations. Reproducible extension activities continue to focus on numbers 1-20, targeting additional skills such as identifying number words, writing numbers, and sequencing number strips. Contents: 5 train engine cards, 5 train caboose cards, 20 number cards, 20 red and green transparent plastic game markers, worksheet, instructions.