I've used this to teach addition and subtraction to K-2 as part of STEM activities at our school. This packet contains manipulatives (domino-like tiles) that can be used to teach addition and subtraction for numbers 1 - 12.
There are also two counting books:
1) one is to color (each number is colored with two pencils to represent two numbers that, together, make up a third: 3 dots colored red and 4 dots colored green will make up a 7, etc.)
2) similar, but incorporates cutting (optional), coloring and gluing tiles in for each number 3 - 12.