Clothespin Math on a clothes hanger! LOVE this. Easy to make, and self explanatory. I'm thinking a wire clothes hanger would work better, so the clothes pins are easy to slide back and forth (almost like an abacus).
Unifix cubes are a concrete representation of addition/number bonds. Building the bond with the Unifix cubes is what develops number sense. Great use for flash cards instead of looking for just memorization
Counting & Addition Activity Tray - open-ended maths activity using counting manipulatives, play dough & a dice, in a dip tray. Opportunities to practise counting, correspondence, matching amounts to numerals and simple addition & subtraction games
Maybe let the kids practice cutting a "Popsicle" to take home for each color of the month. Great for a child who already can identify colors. goes one step further- recognize the word that matches the color! I would pair the spanish words as well :-)