*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.)*