*Solve these maths puzzles as a way to develop logical thinking and pattern matching skills needed to enjoy both computing and maths, while practicing maths too.*

These puzzles were the idea of Daniel, aged 6.

Kriss-kross puzzles combine a love of maths with a love of logic. Given a list of sums, first solve them, then fit them in to the grid. There are also sums to find and do in the pictures.

**Learn about:**

- logical thinking
- pattern matching
- computational thinking
- spreadsheets

**Also for younger children practice and explore:**

- numeracy
- counting
- arithmetic

**Teach as part of:**

- computing, or
- maths

**How to solve them**

Start with any sum where there is only one sum of that length. Then find a place in the grid with that number of entries and fill it in.

Then look for clues! Are there any numbers, +, – or = symbols in the grid that mean only one sum can go there? If so you can fill in another sum. Always check nothing else fits too though. If it does you will need to find a different clue and sum to do first, then come back to this later when you know more.

**RESOURCES**

**Christmas, by Daniel, age 6**

- Puzzle Sheet: Maths Kriss-Kross 1 -Christmas [PDF]
- Raw Puzzle: Raw version of Maths Kriss-Kross 1 Christmas … to include in your own handouts [PDF]
- Solution Sheet: Maths Kriss-Kross 1 – Christmas Solution [PDF]

**Multiplication Kriss Kross, by Daniel**

- Puzzle Sheet: Multiplication Kriss Kross 1 (with multiplication answers) [PDF]
- Puzzle Sheet: Multiplication Kriss Kross 1 (without multiplication answers) [PDF]
- Raw Puzzle:Multiplication Kriss Kross 1 (with multiplication answers) [PDF]
- Raw Puzzle: Raw multiplication kriss kross (without multiplication answers)[PDF]
- Solution Sheet: Solution to Multiplication Kriss Kross 1 [PDF]

**Make your own**

It is also fun to create your own.

- Either do it on squared paper or in a spreadsheet (and practice some IT skills at the same time – see below).
- Put only one digit or symbol in each square
- Always leave one of a different length to all the others as a place to start.
- You need to choose the points they overlap carefully. If overlap symbols are common to lots of equations (especially +, x or =) then there may not be one solution.
- Choose sums so that overlap points will be unique by the time you get to that one.
- Once you have created it,
**evaluate**it. Carefully, try and do it yourself without the answer. Is it possible to do it? Is there only one solution? Double check you have counted the right number of symbols for each. Double check all the sums are correct.

**Make your own in a spreadsheet**

- If using a spreadsheet, you need to change the format of the cell to text so it doesn’t treat = signs as special. Also centre the text in the cells. Change the cell size so they are squares. Also add coloured borders to the cells. Change the text colour from black to white if printing the kiss kross, or make two versions, one with the text deleted for the one to do, the other. Add the clues in a wider column down the side. You can either only allow single digits in a cell (so it is all text) or allow answer cells to actually do the calculations and make those cells non-text.
- Here is a simple example : DIY Maths Kriss Kross