A few days back I gave my students a few”numbers crosses” to solve as part of an escape room activity. I call them number crosses because instead of words you write numbers on the tiles and you describe those numbers in words. They work like puzzles and they can get challenging but they are fun. At the end of the post, I have two number crosses for you to download, some templates, and a google slides version. Read below how to make your own or how your students can create their own.

Here is an example.

Number crosses can be more or less challenging depending on the number-descriptions you choose to write. Also, there is more than one answer in some cases.

For example in the number cross above, 5 across could be 35, 49, however, according to 9 down the number has to be a multiple of 8, so 56 is a good option.

The grid could be bigger, though in my experience smaller number crosses with fewer questions for down and across work better, especially if there are tricky combinations that require more thinking.

**Create your own**

I asked my students to create a number cross using a given template or their own by coloring in the tiles.

I checked and solved all of them, gave them some feedback, and once they were final they were randomly exchanged to be solved by other students.

These are some number-descriptions you can give.

- Ten’s digit is double than the one’s digit.
- Sum of digits ….
- Sum of ten’s and one’s digits is 3 times the hundred digit.
- The digits are consecutive numbers.
- Multiple of ….
- Multiple of …. but not multiple of ….
- Divisible by ….
- Smallest prime number.
- The only even prime number.
- Prime number divisible by 5 (only 5)
- Less than …
- more than ….
- Between … and …
- The digits have difference … (for double digits)
- 1/3 0f …
- Half … and subtract …

It was a fun activity, motivated the students to use mathematical language, and encouraged problem-solving. According to them, and I agree, creating a number cross that works and offers a challenge was more challenging than solving one. Creating a number cross was more work and a lot more learning for the students.

Below are some number crosses to solve with your students and a few templates to create your own.

#### Here is the google slides version

and the print files below