Dinner time is the perfect time for conversations and a great opportunity to engage with your children. The idea of Dinner Time Maths is to add a small spark of maths to the conversation. Discuss a mathematical idea as a family or solve a problem together.

Telling and understanding a maths joke can require a good level of mathematical understanding and therefore telling a maths joke over the dinner table can be a great, light hearted, fun way to teach your children (and perhaps yourself) something new. The more maths you know the more instances you’ll understand internet memes and Big Bang Theory episodes. It feels really good when you ‘get’ a joke about maths concepts.

Here are a few jokes to get you started.

This first one is just for fun and doesn’t require any mathematical knowledge.

Who’s king of the pencil case?

The ruler.

Here is the next joke:

triangle joke

What is funny in this punny comic is firstly the play on words relating to the angles in the triangle. ‘a cute girl’ is a pun on an acute angle which is an angle less than 90. Then the triangle says he is trying to ‘work out the right angle’ and he is a right angled triangle meaning he has one angle which is 90. All right angled triangles have a side which is called the hypotenuse and this is alluded to when they say, ‘hi pot and news’. The hypotenuse is always the longest side in the right angled triangle and is the side opposite the right angle.


This is a great one to introduce your children (and possibly yourselves) to some simple yet quite complex maths concepts. In maths a number can be real or imaginary. It can also be classified as rational or irrational.

Real numbers are pretty much any number you can think of, 2, 5.98, -3.2, 1972 and also fractions are all examples of real numbers.

Real numbers include, whole numbers, rational numbers and irrational numbers (explained further on). So then what is not a real number? We are left with imaginary numbers, infinity and some other special numbers which are not real. If a number is not imaginary then it is real!

The concept of imaginary numbers is very complex. Mathsisfun.com gives us this simple, concise explanation of imaginary numbers.

 Imaginary Numbers

imaginary A number that when squared gives a negative result. Now, if you square any Real Number you always get a positive, or zero, result. For example 2×2=4, and (-2)×(-2)=4 as well. So how can we square a number and get a negative result? Because we “imagine” that we can … and it turns out that such a number, which may seem impossible, is actually useful and can solve real problems. The “unit” imaginary numbers (the same as “1” for Real Numbers) is √(-1) (the square root of minus one), and its symbol is i, or j


A rational number is a number which can be written as a simple fraction, like ¼ or decimal such as 0.25. An irrational number is simply a number which cannot be written as a simple fraction like √3.

In the comic above the symbol i says to π ‘be rational’ because π is an irrational number, it cannot be written as a simple fraction. π says to i ‘get real’ because i is an imaginary number.

We hope you enjoy sharing a maths joke or two with your family over dinner tonight! Share with us any good jokes you come across.

Our inspiration for Dinner Time Maths comes from Laura Bilodeau Overdeck who is the brainchild of Bedtime Math, a brilliant blog dedicated to providing you with ideas to incorporate a maths problem into every day.

Photo credit: davidsilver / Foter.com / CC BY-NC-SA