Really Good Stuff 100 Grid Puzzle Set. New. Never used. Ages 5+. Interactive, colorful way to practice number sense with numbers 1-100. Includes: 60 puzzle pieces 5 mats Storage box 100 grid puzzles align with Common Core State Standards for Mathematics. Counting and Cardinality: K.1 count to 100 by tens and ones K.2 count forward beginning from a given number within the known sequence (instead of having to begin at 1 Numbers and operations in base 10: 1.1 count to 120 starting at any number less than 120. Understand place value: 1.2 understand that the two digits of a two digit number represent amounts of tens and ones. Students can use the puzzles and mats in a variety of ways. Assemble the pieces to make a 100 grid and write in the missing numbers with write on/wipe off markers. Race with another student to see who can fill in all of the missing numbers first or who can put the pieces together first. Write all 100 numbers on the blank side of a mat.