Toddler Mathematics (Toddler Lessons: Part Two)

pythagoras-153530_1280 Continuing (what I have now decided to make) my series in Toddler Lessons, which began with Toddler Laws of Physics, I present Toddler Mathematics.

Toddlers are actually surprisingly good at mathematics. Need convincing? Here are ten maths lessons from toddlers.

1. Addition

Toddlers are excellent at addition: ‘Toddler, why do you have two biscuits? I gave you one biscuit. Is that your little sister’s biscuit?’

2. Subtraction

Subtraction is what happens to toddlers’ shoes, socks, hats and gloves during outings.

3. Positive and negative numbers

(The result of multiplying two negative numbers is a positive number.)

Toddlers have a very clear grasp of the idea that two negatives make a positive. It is why ‘NO, do NOT paint the cat’ means ‘absolutely, please do go ahead and paint the cat – what a wonderful idea’.

4. Percentage

(A number or ratio expressed as a fraction of 100.)

Toddlers use percentages largely to determine how much food their parents actually get to eat. 100% is the percentage of Mummy’s food that belongs to the toddler. 10% is the maximum percentage of Mummy’s food that the toddler is prepared to share with Mummy.

5. The Law of Large Numbers

(According to the Law of Large Numbers, the average of the results obtained from a high number of trials should be close to the expected value, and should become closer the more trials are performed.)

Not many people know this, but toddlers have worked tirelessly on proving the Law of Large Numbers. This is why they like to do a single activity over and over again, selflessly demonstrating results exactly as expected/as obtained two seconds ago. Thanks to the dedicated work of toddler researchers, it has been shown that three billion viewings of a single episode of Peppa Pig does confirm the Law of Large Numbers, producing average results close to the expected value: i.e. 100% of parents rocking in a corner.

6. Ratio

(A relationship showing how much of one thing there is compared to another.)

Ratios are quite important to toddlers. The ratio of vegetables to treats in a toddler’s daily food intake must not be above 1 : 50, or the offered food will be rejected/thrown. (The one vegetable should be a pea.)

7. Whole numbers and fractions

Toddlers like to use Christmas Day to demonstrate the difference between whole numbers and fractions. Their new toys start the day as whole numbers but, following some rigorous ‘banging against the radiator’ tests, are mostly fractions by lunch time. (Coincidentally, the difference between ‘smiling’ and ‘crying’ is also demonstrated on Christmas Day.)

8. Pi

(The ratio of a circle’s circumference to its diameter. Formulas using pi include: the circumference of a circle can be calculated by multiplying twice the radius by pi.)

Toddlers use this formula to calculate the circumference of the ‘Circle of Destruction’ they will be able to form by swinging any toy attached to a piece of string (radius). This enables them to maximise the damage to person, property and cat.

9. Pythagoras’ Theorem

(Used to calculate the length of the sides of a right angled triangle. The square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.)

When toddlers jump from the back of a sofa, the little geniuses employ Pythagoras’ Theorem, using the sum of the squares of the height of the sofa and the depth of the sofa to accurately calculate the length of the stay in hospital to have a plaster cast put on their arm.

10. Inequalities

(A relationship between two values when they are different. For example: a < b (a is less than b), a > b (a is greater than b).)

Inequalities are an area of toddler expertise. In all circumstances, it is vital that a > b, where a = the number of toys a toddler has in his or her possession, and b = the number of toys a toddler’s younger sibling has in his or her possession. Likewise, c < d, where c = the number of layers of clothing a toddler will deign to wear to leave the house, and d = the number of layers of clothing the temperature outside requires to avoid hypothermia.    

(Please Note: As with the science in Toddler Laws of Physics, absolutely no level of mathematical accuracy should be assumed in the contents of this post. In fact, Stephen Hawking is most displeased with both posts.)


You can see other posts in my Toddler Lessons series here.


  1. wendy says:

    I love lessons from the toddler!!All of these are relevant to my toddler, particularly the fractions one. Eagerly awaiting the next lesson…:) xx #TheList

  2. Mrs Tubbs says:

    In Discworld, Terry Pratchett came up with the idea of troll counting. Trolls aren’t too good at figures so counted as one, two, many and lots. Toddler counting seems very similar!

  3. Liv says:

    10% is also the amount of food I put on his plate that he will actually eat. Because mommys plate is 100% tastier even if it contains exactly the same food.

  4. Alice says:

    The two negatives make a positive thing is SO TRUE! I have found it necessary to use the law of substitution in these cases, that is to say rather than instruct the children not to do something, I must instead think of something else that would be preferable, and tell them to do that!
    Very clever, my dear.
    x Alice

  5. OneDad2Sons says:

    Hi, really like this blog. It’s surprising and very true at the same time. One thing I’ve been able to quantify recently through my new FitBit is how many times a day I go up and down the stairs in a day at the weekend!!!!

  6. Sassy says:

    Your ideas for blog posts are just fabulous! I don’t know how you come up with them, but I absolutely love reading them they always brighten up my day! 🙂 xxx #AnythingGoes

  7. Wow this is really clever!! I love the toddler lessons. So much to learn from her!! I love the subtraction one as that happens to us all the time!! Where are the missing parts? Who knows, lol Great post and very funny!! Thanks so much for sharing this at #KCACOLS. I would love to see you again on Sunday! 🙂 x

  8. I love this! My toddler must most definitely be a maths genuis – percentages and the law of large numbers are speciality 😉 Another fab post that had me chuckling as usual. Thanks for linking it up to #MarvMondays. Emily

  9. 7. Whole numbers and fractions this one is my favorite! Besides cracking up all their Christmas toys and hearing the crying for days, they only seem to crack up the quiet toys! The toys that never break are the one’s with annoying sirens or loud sounds. You know the toy that their Uncles buy them in order to torture the parents? Those toys never break!

  10. Your imagination is outstanding!! I love every single one of your posts!! Did Silly Mummy used to work with numbers by any chance?! Your grasp of maths almost rivals that of the toddlers!! Yes, it’s been gradually dawning on me that I do, indeed, have 2 tiny maths genius’ in my household! They are especially adept at the giving me exactly 10% of my own food! I’m so glad this has been turned into a series! Thanks for sharing with #bigpinklink!

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