So many ways to cultivate this understanding of numbers. I have three words for the best way: conversation in context. Communication going both ways. The best context? A natural one. An organic one, that is, that emerges naturally. This can take place during a structured lesson (therefore the structure will have to be accommodating of genuine conversation), but for preschoolers, play will do just fine. And while some of the times, you may initiate the conversation on quantity/addition/subtraction etc. based on whatever opportunity emerges to make observations or ask questions (you are the grown up, after all) eventually, your child will do the same. Initiate conversations about math. You can introduce synonyms for addition and subtraction, as well. All of this becomes perfectly natural. The beginnings of academic math become engrained in the mind of the child naturally. Not only is it thus more likely to stick over time, the understanding of quantity etc is more easily transferred across other contexts such as conversations with others, play with others, formal learning of math, and comprehension applied. So, it continues to be important to support the concept of preschool learning as a primarily child-centred process of engagement that honours the intellect of the child.