I have successfully used the Everyday Counts Calendar Math program for 3 years. I aligned its components with our state standards to make calendar a powerful component of math. Below are resources I use regularly.

Calendar Math Resources Place Value 1 Place Value 2 Tally Marks Even and Odd Coin Counter Hundred Board (partial) Rounding Chart Computations Calendar Math Task Cards(idea from 2nd Grade Club) Calendar Labels Calendar Seasons Calendar Weather Birthday Graph Birthday Graphers Calendar Months Calendar Days Calendar Events Calendar Events Color