While waiting for his big brother at the orthodontist, my little boy, C, had the following conversation…
Dr. T: How old are you, cutie?
C: I’m three!
Dr. T: How old is your brother (pointing towards my thirteen year old)
C: Four!
This was such a proud mama moment for me!
Now you may ask yourself, “Why is she getting all excited over this? Clearly, he is not four. Why is she so proud of her little boy?”
There are a number of reasons why this is a critical step towards numeracy. I truly believe that if you start children purposefully thinking about numbers early on, their chance for success in mathematics increases dramatically. So let’s highlight a few of the big ideas C is working towards.

1. Cardinality– This is the idea that the number being used is measuring some amount. It answers the question, “How many?” For example, I can ask my son, “How many bears do you see?” He would count them one by one until he got to the number six. That last number, 6, tells you the number of bears in the set. This is a big deal! The child is no longer counting from memorization; he is recognizing that the number relates to a certain amount of “things”. The more things you have, the further you have to count. C recognized that his brother was older (or “bigger”). Therefore, his brother was tagged to a number after the one he identified with, three. He did not know how many more to go, just that he had to choose a number beyond his own. Cool.
2. Inclusion– This is the idea that the number labeling “how many objects” in a group includes all of the preceding numbers. So even though we have six bears, we can also think of it as “one and some more”, “two and some more”, “three and some more”, and so on. This is critical for addition and subtraction. If I have the number 14, I can think about it as “ten and four more”, which helps me when I want to add or subtract and regroup to make the problem easier. C knew that his brother was older, and therefore had to include his age (three) and some more. Again, he isn’t at the point of knowing how much more, but is on his way. Awesome.
3. Magnitude– The size of the object. In this case, a number (or value) given to a quantity (age) for the purpose of comparing with another quantity. This idea is instrumental for estimation, particularly with very large and very small numbers. In fact, one of the posts requested of me to write is helping students compare fractions. If a child does not know the relative size of the number they are considering then it is very difficult to compare, operate or manipulate it with any real fluency or number sense. How do I know my answer is reasonable if I haven’t a clue what the numbers I am working with represent??? For C, he was able to recognize that his brother had to be a larger quantity than three, because he is older. Super rad!
These three ideas are certainly related, but each has a different feel. You can work with them simultaneously, so long as there is purpose to the questions and tasks you present to your kids. Below are some simple, but powerful, activities you can play with your little ones to build these concepts. I choose the games that you can take on the road, to the doctor’s office, to a restaurant, etc. Instead of sitting around being squirrelly, play a game while you wait. Even five minutes will have a significant impact!
1. Count and Check: Grab a handful of ANYTHING (balls, pennies, beans, cheerios, etc) and ask your child to count how many. Make sure the amount of objects is appropriate. (For example, C is working on objects through 5.) When he finishes counting the last object, ask, “How many _____ are there?” If he cannot answer, that is okay! He is working towards cardinality. He is able to say the objects one by one (which is called one to one correspondence), but hasn’t figured out that the last number he says represents the entire amount. Have him count again, and ask again. If he cannot answer again, say, “There are (say the amount) ______ here.” You can play this at the grocery store (count the apples, bananas, etc), setting the table (How many forks?), etc.
2. Match Me! Grab a die (one dice) and a handful of ANYTHING in a baggie. (I typically do this with pennies at restaurant.) Have your child roll the die. Let’s say she rolls a five. She takes out that many pennies and lays them out for you to see. Ask her to count them one-by-one to make sure she has five. At the end ask, “How many pennies do you have?” If she doesn’t know, that is okay! Have her recount, then ask again. If she still isn’t able to tell you, say, “I see you have five pennies.” Make sure you roll next and model for your child. Take turns until you get bored or dinner comes!
To bring the difficulty up, after playing each of these, ask, “If I gave you one more item, how many would you have?” This brings in the concepts of magnitude and inclusion! If your child has to recount with one more added in, that is fine! You know he’s got it when he can answer quickly without physically adding in another item and recounting.
Need another level of difficulty? Ask, “If I took away one of the items, how many will be left?” Same idea, but working backwards, and just as important!