Getallenlijn verder met 10 How to make a Montessori "teen" board (Adding n = teen number) >>Take it further by adding 10 to other double digit numbers. Could make multiple sets for centers out of index cards.

equation cards - with the 'answer' at the top of the card, children will need to add up the equations to see if it equates to the answer. if it does, clip a peg next to the equation.