This set corresponds with our Winter Penguin and Polar Bear 10 Frame Counting Mats (1-10). This set includes 2 designs, 3 frame options (pictures and numbers, pictures without numbers, and no pictures with numbers) number cards 11-20, a subtraction and an addition worksheet for numbers 11-20. We suggest using snowflake foam stickers or white puffballs as manipulatives. Our store also carries a bundle set 1-20 at a discounted price. This math activity aligns with Common Core.