After your child has begun to understand the basic math concepts of Number Sense, Representation, Shapes, Measurement and Patterns, you can add in some foundations of addition and subtraction in any everyday conversation.
Addition in the blocks corner: “Your tower is four blocks tall. If you add one more block, how tall will it be? “Can you make a tower of four duplos or unifix cubes and one with two duplos… now, if you put those two towers together, how tall will it be?”
Subtraction at snack time: “you have five grapes – if you eat one, how many will be left?” “I said you could have two cookies, and you took three – how many do you need to put away to save for another time?”
Waiting at pick-up time: “you made two paintings, and she made three paintings. Who made more? How many paintings did you make all together?”
Bedtime Stories: “I usually read you two bedtime stories, and Grandpa usually reads you three. Who reads you more stories? How many more does he read?”
You can practice lots of this adding and taking away before you introduce symbols.
This video illustrates one approach to introducing math symbols. Have a child count out some objects on plate A and more objects on plate B, then put a + symbol in between the plates, and an = symbol after plate B and set down plate C. The child counts all the pieces as she moves them to the final plate, and can see that 4+6=10.
Don’t turn this into work! It can be just a fun and simple activity that you do together.