YOUR TAX-DEDUCTIBLE CONTRIBUTION PURCHASES THIS ITEM FOR OCS - THANK YOU! Just reach into the mystery box to pick a math problemand target Common Core State Standards in just a few minutes each day! Great for daily warm-ups, extra practice, math centers and more, our set includes 100 question cards featuring fun-to-solve riddles, puzzles and word problemsall targeting first grade Common Core State Standards for math. The set even includes a guide with an answer key for easy self-checking, plus a 7 1/2"w x 7 1/2"d x 6 1/2"h mystery box.