Give clues to identify a number from the calendar. Mystery number is a great way to reinforce vocabulary from the current unit of study in math. For example, if you are studying prime numbers, state the clue that this number is or is not a prime number. If you are studying geometry, the clues could revolve around the number of sides a polygon has. For example, if you want student to guess the number "Five," tell the students the mystery number has more sides than a quadrilateral. This game can be adapted to any level you are teaching. With the primary grades, your clues could reveal the number is an even or odd number, or the mystery number is more than 6 plus 4.
As part of the daily routine, write the date with the year in words and numbers. Write the day of the month in standard notation, just the numbers, written in words and expanded notation, the number broken apart by place value. For example, for the 24th of the month, you would write "24," "twenty-four" and "20 + 4." Ask the students to give you the fact families for the date, such as "20 + 4," "4 + 20," "24 - 4" and "24 - 20."
Have the students write an equation in which the sum, difference, product and quotient are the day of the month. For example, if the date is the 10, the students could share "4 + 6 = 10," "14 - 4 = 10," "5 x 2 = 10" and "40/4 = 10." For upper-elementary students, ask them to use more numbers in their equation or include more than one operation in their number sentences. A real challenge would be to ask them to include all four operations and find the day of month as the answer to the multi-step equation.
Have large coins, actual coins or coins to stick onto the calendar to represent the date with coins. Have the students show all the different coin combinations that are possible to make the date. The date of the 7th would result in to two combinations, a nickel and two pennies and seven pennies. This activity reinforces money skills. The repetition of finding the combination of coins daily helps all of the students understand the value of money.