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.