When Fiona was ten she was the Waikato Regional Game Twenty Four Champion. Such was her prowess and dedication to her sport that she would probably have gone all the way to a national title had their been the forum for her to progress beyond the contest at the Hamilton McDonald’s. At the time small Fiona recorded in her diary: “Can you believe it, diary? Is it really true?… I am the happiest person in the world.”

So, as you can imagine, Fiona was pleased to share this game at Mariposas. We’d brought it from home thinking we could use it in maths class. But the modest multiplication and division skills it requires puts it out of reach of most at the school. Still for the older ones, and those who are more competitively inclined, it’ll be great. Fiona even let them win a couple of rounds.

adorable little Fiona McAlister

I wonder how your teacher from then would feel, to know how that learning has travelled.

The world is full of things I know nothing about. 24 game the latest example.

I think you could get the hang of this one Derek LeDayn. You have to use the basic operations (add, subtract, multiply, divide) and use up all the numbers on the card to make twenty four.

Is the experience like scrabble or crosswords? (tedious)

This may be my favourite blog post yet!

Derek LeDayn no, it’s more fast paced. I asked Fiona for a comparison but she said nothing compares.

Hmm, promising.

You get four single digit numbers. Using all of them, and any combination of +, -, ×, and ÷ you like, make the result 24.

E.g. given 1, 2, 3, 4 you might say:

1 + 2 = 3

3 + 3 = 6

6 x 4 = 24

So, each round is very quick.

Some are very easy, others are harder.

Favourite 24 puzzles for me were:

3, 3, 7, 7

and

1, 3, 4, 6

Exponents are cheating Graeme.

quite right. There are non-exponent answers to both of those puzzles.

I especially like the 3, 3, 7, 7 puzzle because there are just so few options with two double-ups.

Hm. Will have to ponder that one!

Don’t look it up. You’ll be really pleased with yourself when you figure them out

You need brackets! Not sure that’s allowed…

I will have to have a duel at some point – I achieved in some level of competition at Intermediate. I play with car number plates too sometimes (swap 0 for other numbers), but it was easier with the AA1234 style plates

You don’t need brackets. You just do it as a bunch of separate equations. Isn’t that how it works?

E.g. given 1, 2, 3, 4 you might say:

1 + 2 = 3

3 + 3 = 6

6 x 4 = 24

I don’t recall there being a rule about having to put them in proper BEDMAS order in a single equation. Have I been playing wrong all these years?

Banning this sort of solution would seriously limit the number of playable puzzles.

Okay so the best solution I have come up with for 7, 7, 3, 3 is:

3/7 = 0.42857143

0.42857143 + 3 = 3.42857143

3.42857143 * 7 = 24

Putting it like that you’re right you don’t need brackets. Success. Hurrah.

Well done. I needed a hint from the person who set it for me to get it: “work backwards”. Hmm, 24÷3=8. No help. 24÷7? 3 with 3 left over, no wait, 3 and three-sevenths! Huzzah.

The other one is much harder – Maybe a Fiona-level puzzle