During the Great Depression, Alfred Butts, an unemployed architect, decided to invent a board game. He discovered that games fell into three categories: number games, such as dice and bingo; move games, such as chess; and word games, such as anagrams.

Butts wanted to devise a game that was half luck and half skill and integrated the vocabulary skills of crossword puzzles and anagrams, with the additional element of chance. Lexico was born. After many refusals and a number of name changes, the game of Scrabble eventually hit the big time and has since sold more than 100 million sets in 29 languages.

In the classroom, Scrabble is often used as a fun and innovative way for children to develop vocabulary and spelling, but how often is it used for promoting maths skills? The obvious and explicit maths involved in a game of Scrabble includes doubling, tripling and a lot of scoring. That’s maths through the front door, but with a bit of creative thinking there are many rich opportunities for maths through the back door too, and even the skylight.

Let’s start with the 15x15 square board. How many squares are there? Think again if you said 225. What about squares within squares? It’s a tough investigation in itself. Why not practice co-ordinates? The board has numbers and letters printed on the axes, so there are rich opportunities to describe positions. So, what about the letters? There are 98 tiles and two blanks. What’s the probability of drawing out a vowel, seven consonants or the letter L? How many letters have both vertical and horizontal symmetry? Which have rotational symmetry? Does x have two or four lines of symmetry? Each letter of the alphabet is assigned a particular numerical value, which is heaven sent for mathematicians. The possibilities are endless.

So where to start? Scrabble is most likely to be used with a small focus group of children and doesn’t even have to be played as a word game. One game is Baggy. The bag of tiles is placed in the middle of the table and players take it in turns to be the “number boss” who calls out an instruction such as “highest number”. Each player draws four letters from the bag and whoever makes the highest number scores one point. The letters are returned to the bag and a new game is played using different instructions such as: pick four letters and find the biggest digital root; pick four tiles and multiply together; pick four tiles, make two two-digit numbers and subtract to get the lowest difference; pick four tiles, make one three-digit number and divide by the fourth number. The scenarios are delicious.

As a maths word game Scrabble really comes into its own. Playing the game with just maths vocabulary is something to aim for, but a traditional game with bonuses for including maths words is likely to work well. What additions and creative twists you make to the rules will reflect the abilities you’re striving to cater for. A good place to start is to change the premium values of double and triple-letter word scores to include multiples of six, seven, eight and nine. A sticky label here and there can dramatically alter the genetic make-up of the board and potential scoring.

But it is number recognition that should be seized upon.

Back door maths examples include: If you can make a maths word that contains the only even prime then double your score (eg decimal). This rule soon teaches children that two is the only even prime and that the letter D is a valuable letter to have. Other examples worth trying include: If you can make a word that contains two or more composite numbers then score a bonus of 10 points (eg Helix). If you make a word that adds up to a baker’s dozen, triple your score (eg zero, weight). The trick is not to have too many rules.

Skylight maths comes from the children themselves. If we can inspire them to think of their own rules and get them playing in creative ways then we will be milking maths for all its worth. Ask them to have a go at this question to get them thinking and exploring: What positive integer, when spelled out, has a Scrabble score equal to that integer? Answer: 12 (one, four, one, one, four, one).

So if you’re looking for a way to improve children’s generic maths skills, as well as their analytical and problem-solving thinking, then count Scrabble in and watch the difference. The word is that numbers are fun.