This text is based on my response to a question on Quora, slightly expanded:
As a mathematician, how would you mentor your child and help her to learn, do and live mathematics in her free time as she is growing up?
I write from the position of a mathematician about what a mathematician can do for her child.
First of all, a mathematician understands and can use the fact of life non-mathematicians are not aware of:
Mathematics is done by the subconscious.
Encourage in your child, and help her, to develop all kinds of intuition, guesswork (with subsequent checking, whenever possible, of the correctness of the guess). Help her to train her vision of the world, see [mathematical] relations in the world, identify mathematical structures present in the world.
As you can see, this immediately moves the discussion away from school and traditional approaches used in the traditional school education. In fact, this is more of an advice for home-schoolers, especially those who themselves have a sufficient mathematics background. The latter does not mean having a B.Sc. in mathematics; for example, reading economics at Cambridge, UK, suffices.
However, mathematical games briefly described here are not a replacement for a systematic course of mathematics.
But this in-family “protomathematics” could perhaps open to a child a door to mathematical thinking well above the demands of standard school curricula.
What follows are a few random examples, chosen from what I did myself with my (grand)children or had seen my colleagues doing with their (young, pre-school or primary school age) children.
Adult spends some quality time with Child, aged between 3 and 4, in a garden, watching insects and ants, and discussing with Child how the world looks from the ant’s viewpoint: that the tree trunk is like a street, and patches of algae and of moss on the bark are like lawns and bushes along the street. Child: “and these branches are like side streets”.
As you can see, a gentle introduction to mathematics can start just by watching the world, in this specific case insects and flowers in a garden.
A child needs to develop a habit of attentively looking at the world; to achieve that, it helps when an adult looks with him, and they discuss what they see.
Mathematics, in one of its many aspects, is a specific vision of the world.
Basic (but mathematically very deep) concepts of similarity and scaling are accessible to a 4 year old child.
The former is erased (with most of geometry) from school teaching, the latter was never properly taught. Euclid’s proof of the Pythagoras Theorem as given in Book 6 of Elements is an example of a scaling argument.
Let us look at one of the simplest examples of fixed point theorems (I have seen it in some popular books on mathematics):
If a (topographic or geographic) map is placed on another map of the same territory, but of larger scale, then it is possible to stick a pin in the both maps which goes through images of the same point (location) of the surface of Earth.
What I’ll give you now is not a proof but an immediately obvious explanation:
Imagine that you an ant and stand on the bigger map which is like a surface of the Earth for you, and you hold the smaller map in your hands; just mark your location on it.
Further development of the theme of maps:
Adult uses every opportunity to explain to Child the structure of actual streets in a big city: street signs, house numbers which go in progression and are odd on one side of the street and even on the other side. A year later, Child is able to confidently guide Adult across a unknown part of the city using a standard AZ map.
Observing an ant on a tree helped. This was an encouraging sign of mathematical development.
Of course, Child’s ability to read is useful. Street names, all kinds of shop signs provide an excellent material for reading and proof that reading gives information about the world.
In a supportive family environment, a child can learn to read by the age of 4 or 5—even in English with its inane orthography. Social class issues creep in here: this is realistic mostly in families of well educated middle class professionals. Sufficient disposable income for buying “quality time” with children (say, by inviting an au pair or hiring a caretaker of some kind for more routine tasks) definitely helps.
And the last episode in development of this theme of maps, a conversation on a street:
Adult: “Look at the name of this street. Does it tell you anything?”
Child: “Yes! Its end meets the street where Grandma lives, just over the corner!”
Adult: “And do you remember, what kind of house numbers there, large or
small?”
Child: “Small!”
Adult: “So, in what direction we have to go?”
Child looks at house numbers around and confidently points: “There!”
More about rearing and writing:
Adult and Child (aged 5) send to each other, from opposite corners of a sofa, small strips of paper with messages written in a substitution cipher: each letter is substituted by the next one (cyclically, z is substituted by a). Suddenly Child exclaims:
“And I invented my own cipher — each letter is replaced by the previous one!”
IMHO, this would later help Child to understand algebraic notation where numbers are substituted by letters. It is worth remembering that François Viète, the inventor of algebraic notation, was the first cryptographer and cryptanalyst known to us by name. He served to King Henry IV of France. Viète’s deciphering of intercepted diplomatic correspondence directly influenced European politics of his time. The King of Spain famously complained to the Pope that Viète sold his soul to the Devil.
Some time later, at the age about 7, Child can handle variables in Scratch, a toy programming language for kids.
Child is invited to guess weight of every household object she can handle by weighing it in hand and check the result by weighing on scales. The same with temperature of water in the bath, checked by a thermometer. Or temperature outside the house.
Further,
All kinds of estimates with subsequent checking: how many steps are in this staircase?
How many steps are to the end of the street?
How to estimate the number of cars in the parking lot without counting them all?
I can add cooking and baking, as a family activity, if Child is entrusted with control of numerical aspects of the recipe: how many spoons of sugar?
Lego:
Playing Lego (with child of 4). Adult encourages Child to pick correct bricks (say, 2 by 3 studs) without looking at them, by touch only. They together follow step-by-step instruction in the manual. And steps are numbered!
Building a symmetric model (say, a plane), Adult builds the left wing, Child builds the right wing by mirroring Adult.
Very soon Child starts picking details of correct orientation even before Adult touches his detail. (Orientation is an exceptionally important concept in geometry which is not even mentioned at school.)
Lego is a great propaedeutic for Scratch, a toy programming language for kids where computer programs are built on the screen from logic blocs which intentionally made looking as bricks in Lego.
And the real unadulterated fun, fun, fun:
Playing Snakes and Ladders with two dices. A player can pick one of the values or their sum. The catch is that, for winning the game, 100 has to be hit without overshooting—for otherwise the player gets back to the beginning, the path is circular, 97+6 = 3.
A fast, furious, and vicious game which trains tactical thinking.
Actually the rules of Snakes and Ladders can be changed in a variety of ways. Adult encourages Child to invent her own rules. Crucially, the new rules need to be agreed and written down before the start of the game.
A useful meta-activity: ask Child to compare two sets of rules: which one produces a more exciting game?
A jigsaw with a clear geometric structure could be very useful. The classical London Tube map is excellent, especially if Adult and Child work together and agree to ignore the white space. But perhaps the London Tube is best for kids who live in London.
I can continue this list, but, I hope, it already gives some idea.
And I have no idea how all that could be done at school.
Within the family—no problem. In small and friendly mathematical circles—it is also OK.
But in school?
And, finally, some general advice:
Never ever distract your child when he/she just sits and thinks.
This post was previously published on Substack.