Here is the sudoku question our teams - the squiggles and the bows - worked out today. They had 20 minutes and both teams managed to crack it, but the squiggles were quicker! The puzzle credit goes to Thomas Snyder. The rules are the same as sudoku. The numbers to be entered are 1-5. The two numbers that you must find to fill in the bold rectangles with the small digits in their left hand corners must make that little number when added together or taken away from each other. (In subtraction, take the smaller number from the bigger number). The correct position for the numbers you fill into the bolded boxes could be either order of those numbers. The - and + signs next to that little numbers in those corners are not part of the number, they simply denote what calculation you do. The boxes that do not have a bolded outline and a little number in the corner (in this case the middle bit) simply take whatever number 1-5 fulfills the sudoku rule that no number can repeat in a column or in a row. Any questions, write a comment. Happy puzzling and let us know how you get on. (Ignore the A and the B in the picture). Why not use the comment box to tell us how long it took you to finish the puzzle. Don’t tell us the answer, though - we already know it : ) and we want to give others a go at completing the puzzle without the temptation to give up and check the answer when the going gets tough.

Discussion

We haven't posted anything here for a while because we have been super busy creating competitions, launching our first maths league and coaching. Tomorrow, we will push on to a new frontier when the St Peter's maths team starts to design their maths buddies programme. Practically, that means our 9-11 year old mathletes will curate and create maths games for their younger school mates. Here are some warm up games we found online while doing research. https://mathforlove.com/2015/05/quick-physical-games-for-the-math-classroom/ The games come from Mathsforlove, who look v cool - right up our street, in fact. Check them out https://mathforlove.com/

Great stuff @joshster . I am going to delete the comment with your (correct) answer, so that others can give this a try too. How fast did you solve it? Perhaps next time, just post the number of minutes or seconds it took you to get the question. I definitely counted my solution time in minutes, but you'd be amazed what grand masters can do.

No problem!

It actually took me a few minutes (maybe ten-ish?!) because I hadn't done one before and I thought the minuses had to be big number on the left/top, and then I also thought the middle "S" area maybe had to have one of each number 1-2-3-4-5 in it too! (So I came to a couple impossible situations before realizing the rules and starting over.)

Thanks - that’s helpful feedback. I am going to clarify the rules

I did this puzzle with my 10 year old son in about ten minutes, and he found it interesting, as a twist on Sudoku. It was a clear way to show that constraints on number sets can come in many forms, and yet still resolve to a single solution. The one tricky bit was parsing the instructions, which we found a little unclear. A suggested rephrasing follows:

This puzzle follows the rules of Sudoku, with one extra rule. You will notice that the board has several pairs of squares, each surrounded by a bold border. For each of these pairs, there is a small number in the top left corner, followed by either '+' or '-': let's call this the 'total'. This means that either the sum (for '+') or the difference (for '-') of the two numbers in the pair of squares must be the total.

This extra information will be enough for you to solve the entire board!